Hi Jonas,

Have you confirmed you have the correct file permissions set on the relevant folders?

http://umbraco.org/documentation/books/important-files-and-folder-structure/permissions

Matt

The file permissions are also correct, and have checked with Fiddler, so no files are missing or have wrong permissons.

Same issue here;

Fresh Umbraco 4.5 install, correct permissions and copied after unblocking rar file.
Situation is an Server 2008, Webfarm with IIS 7 Shared Config, Failover SQL 2008, .net 4.0. Both tested medium and full trust.

Other older versions working like a charm!

Any ideas?

Thanks in advance

Same problem I had - See here

http://our.umbraco.org/forum/core/41-feedback/10732-Fresh-45-Install-No-Trees

Do I need to do a complete new installation including database after uploaded the files from a "Unblocked" ZIP?, have only tried to upload the "Unblocked" files again without reinstalling the database, and that doesn't solve my problem.

Start again... I literally deleted the site, dropped all the tables and went through the install again.

Any solution to this? 

Just installed everything - installation went fine, but when I log into Umbraco all the top level sections are empty!

Win XP Pro SP 3, IIS 5.1, .Net 4

I just had the same problem, I got the nodes back, Im not exactly sure when though. I did all of the following:

Unblocked the zip, and extracted all files again to my site folder

Temporarly removed some media upload dll's (Nibble.Umb.ZipUpload, noerd.Umb.DataTypes.multipleFileUpload, Dascoba.Umb.FileManager

Restarted W3SVC service

Republished the entire site /umbraco/dialogs/republish.aspx?xml=true

Win 7 IIS 7 Net 3.5

I hope you get your site up!

Edit : stroked the things that seems to have nothing to do with this

Thanks Jonas,

I'll give it a try but does anyone know the root cause of this?

Can't see any errors logged in the db or event log . ....

Have reinstalled everything again, but with no luck. (Uploaded the files in different ways also)

The site is running on medium trust, and i have changed umbracoUseMediumTrust to true, but when I uncomment <trust level="Medium" originUrl=".*" /> i get:

"This configuration section cannot be used at this path.  This happens when the site administrator has locked access to this section using <location allowOverride="false"> from an inherited configuration file."

Is this section required? (Site is running on Windows 2008 IIS 7.5, ASP.NET user has modify rights)

Bump!

Same problem here. I am also running on Windows 2008 IIS 7.5, ASP.NET 4.0. Application pool is configured to Network Service -user with modify rights 

Update

Don't know what happened but when I restarted my machine last night, hey presto, all the top-level section child nodes reappeared!

I did the unblock thing and unzipped using PKZIP - neither of which had an immediate affect. But it seems a good old restart kicked it into action.

Bizarre.

Update

Yes, it seems that the problem was BLOCKED dll's in the cms ZIP file. 

I solved this by taking installation zip properties and unblocked the zip. Then I unzipped and took bin folder from it to my webroot. After that I restarted IIS and now tree works fine. 

Notice you need to restart IIS after unblocking DLL's.

I have the same issue.  http://screencast.com/t/OTc4YjEzY

@Jonas

Did you ever get this version to run OK at Binero? I´ve got the same issue at them.

No Mike, I haven't been able to get it work at Binero.

There is no way to set permissions on files in the new control panel at Binero, and they say that the app pool account has full access, and I doesn't get any access denied when running MS Fiddler. (Maybe i don't see all Ajax requests)

Have tried to upload the files with different FTP clients, and unblock the ZIP before.

Have moved the ClientDependency folder without luck

Is there any way to profile this problem?, since it looks like there can be different causes.

Hope the Umbraco Team will look at this after the vacation since there are many people having this problem.

/Jonas

I'm getting similar issues, can you checks something for me?

Look for requests to TreeDataService.ashx using Fiddler or Firebug, and check if it's returning anything more than quare brackets.

http://YOURSITE.Com/umbraco/webservices/TreeDataService.ashx?rnd=194da7e60f0a47fe8ec0e064a9151813&id=-1&contextMenu=true&isDialog=false&app=member&rnd2=97

I had a perfectly working website that i moved to a different server and then this issue popped up...

Getting:

Invalid at the top level of the document. Error processing resource 'http://domain.se/umbraco/webservices/TreeDataService.a...
[]

If you haven't already: Allow .NET 4.0.3 under the ISAPI Restrictions:

I had it checked earlier today and the settings where fine, now i also tried the same with a clean install and it just isn't working on the 64bit server. everything is fine on the other.

The production server is running several 4.0.3 websites without issues, these are the first 4.5.1 websites we try to put online.

Something else i noticed, when i try to install the Runway modules, i get this error during a clean installation:

Hi

I have the same issue with empty tree nodes

I have tried to enable .NET 4.0.3 in ISAPI filters, but no luck.

I how ever, have tried to locate the files on a local drive it works fine, but when the files are located on a share, the nodes are gone?

Please vote on existing issues on Codeplex or register new that fit your desciption. Nothing happen here, that´s for sure.

Lars: i'm having this tested today, but i can confirm that our working installation had all files on filesystem and the production uses shares for load balancing.

Sounds like things just got a lot worse if you want to create a load-balanced setup with both staging and live environments...

New issue added to Codeplex regarding this problem.

http://umbraco.codeplex.com/workitem/28405

Nice, have voted for the codeplex issue.

Tested this and indeed we only have the issue when the files are on a share, i'm looking into setting these permissions properly, things have changed for .NET 4 so it seems:

sorry, i mean to reply to this more active post..

----

Removing Dascoba.Umb.FileManager from /bin helped me with empty content nodes.

Hi

I do not have a file with that name in my /bin folder?

I use v5.4.1 (.NET 4)

I have no file containing dascoba at all, and no files in the /bin containing "File"

/ nOrphf

I tried to debug it, basically

I find that in the file =>

"\umbraco-74794\releases\umbraco 4.5\umbraco\businesslogic\Utils\TypeResolver.cs"

(as i cannot build 4.5.1 in vs2010, i use 4.5 to debug)

line 99

Assembly assembly = Assembly.LoadFile(fileName);

it tries to load *.dll from the bin folder, when the bin is reside in shared folder like \\fileshare\wwwroot

it throw error message of:

"An attempt was made to load an assembly from a network location which would have caused the assembly to be sandboxed in previous versions of the .NET Framework. This release of the .NET Framework does not enable CAS policy by default, so this load may be dangerous. If this load is not intended to sandbox the assembly, please enable the loadFromRemoteSources switch. See http://go.microsoft.com/fwlink/?LinkId=155569 for more information."

I am not an expert in MediumTrust, still struggling...

Ok,

I believe the sanbox created in:

"public static string[] GetAssignablesFromType<T>(string[] files)" is not liked by .net 4 for some reason

i have commented out the code of following:

            if ((!GlobalSettings.UseMediumTrust) && (GlobalSettings.ApplicationTrustLevel > AspNetHostingPermissionLevel.Medium)) {
                AppDomainSetup domainSetup = new AppDomainSetup();
                domainSetup.ApplicationBase = AppDomain.CurrentDomain.SetupInformation.ApplicationBase;
                domainSetup.ApplicationName = "Umbraco_Sandbox_" + Guid.NewGuid();
                domainSetup.ConfigurationFile = AppDomain.CurrentDomain.SetupInformation.ConfigurationFile;

                domainSetup.DynamicBase = AppDomain.CurrentDomain.SetupInformation.DynamicBase;
                domainSetup.LicenseFile = AppDomain.CurrentDomain.SetupInformation.LicenseFile;
                domainSetup.LoaderOptimization = AppDomain.CurrentDomain.SetupInformation.LoaderOptimization;
                domainSetup.PrivateBinPath = AppDomain.CurrentDomain.SetupInformation.PrivateBinPath;
                domainSetup.PrivateBinPathProbe = AppDomain.CurrentDomain.SetupInformation.PrivateBinPathProbe;
                domainSetup.ShadowCopyFiles = "false";

                sandbox = AppDomain.CreateDomain("Sandbox", AppDomain.CurrentDomain.Evidence, domainSetup);
            }

which make 4.5 works for me on \\fileshare\wwwroot, however I cannot build 4.5.1 in vs2010, and it is not really a 'fix'.

as mentioned not an expert, waiting for a proper fix.

My umbraco is running in Full Trust, and set to medium trust breaks some other places...

Could someone from the Core team please make some comments regarding this issue. Is it a Umbraco issue or is it an hosting issue?

Hi everyone, thanks for your patience with this item. It looks confirmed from reading the thread, but could everyone double-check that they are seeing this issue if they are running their site root from a share? If so I'll update this item http://umbraco.codeplex.com/workitem/28405 to reflect it and we'll organise getting this looked into

Thanks

Alex

Hi

I have extracted the files to my share, setup IIS, no nodes.
Copied the files from the share, to C drive, then changed only home directory in IIS, and the nodes are there, change home dirctory back to file share, and nodes gone again.

/nOrphf

Have contacted my hosting company so they can verify that the web files are placed on a share.

@Jonas.
I have talked to Binero.se a few times the last week and I can confirm that they are using a "share" like this

APPL_PHYSICAL_PATH \\10.0.0.10\vol100\content\xx\xxxxxx\umbracoinstallation.se\public_html\

You can see it in the trace if you create an runtime error. An easy on is just to change your database password to an invalid one and visit your site. Then the path will show in the trace.

Alex: I can also confirm tests where a site runs perfectly when running from filesystem, and blank nodes in the backend when running from shares.

Hi everyone

For those who are experiencing this problem running .NET 4 from a share, please could you try adding to your web.config file as per:

<configuration>
  <runtime>
    <loadFromRemoteSources enabled="true" />

This is documented at http://msdn.microsoft.com/en-us/library/dd409252(VS.100).aspx

Please let us know how you get on; Per has added this information to the upgrade guide at http://our.umbraco.org/wiki/install-and-setup/upgrading-an-umbraco-installation

If you're getting empty trees and it's not to do with the above, and not to do with blocked zip files, please let us know too.

Update: This tweak may only apply to hosting in a Full Trust environment.

Update 2: Be careful if you ever edit a post on Our in Chrome with a Code snippet, it gets blanked!

Thanks

Alex

The <loadFromRemoteSources enabled="true" /> fix doesn't solve the empty tree nodes at hosting binero.se

/Jonas

Sorry to say but it didn´t help. It´s confirmd not working in the comments also on the page that you refer to

"Why can't I run code from my own local area network? BTY, I set this and it still doesn't work. Please don't blame me that it doesn't work BTW. It's your fault with your stupid security.
"

"The most annoying part is that this doens't work right with Windows own gp folder redirection. What a pain."

If you guy´s at Umbraco can´t recreate this issue and want a hosting account where this error exist I would be more than happy to give you one that you can test on.

@Jonas @Mike are you both running in Full Trust?

One potential workaround for now, if it is applicable to you, is that you run the site in .NET 3.5 (ASP.NET 2) if your hosts allow you to switch the AppPool mode and your code is compatible. Just trying to think of workarounds for now until we can resolve this issue

Yes, Binero.se are running .NET 4.0 in full trust.

Hi,

Our envirement is running .NET 4 in full trust mode as default, if the customer want to change back to .NET 2.0/3.5 (medium trust) that is an option which is available, but the customer needs to contact our techcnical support team at [email protected].

If the Umbraco team wants test accounts, I would be gladly to fix that for you.

We are as well running up to 30 IIS-nodes on each cluster, and the whole enivrement is loadbalanced with F5 BigIP, our storage is from NetApp and we have connected all the volumes via NFS.

We got at the moment 7 tickets regarding issues with Umbraco in this envirement so it would be nice with a fix. If you need any following up questions do not hesitate to contact me.

Regards, Kjetil
Binero AB

@kjetil, could you email me at pph @ umbraco dk a test account would make it so much easier to replicate the issue

thanks

Hi all,

  Shall we use the content of the xslt in the template like want to access the value of the related link(url)?

@per,

The production server of:

windows 2008 r2 64bit (IIS) + shared storage (SAN)

or local development environment

windows 7 ultimate 64bit (IIS) + windows 2008 shared folder (storage)

both have the issue, I am not sure if it is related to 64bit (when debug 64bit, VS will stop you from doing something you can with 32bit)

According to my debug, it seems to related to do with the creation of an appdomain. Also not all project is targeting .net 4, not sure whether this cause an issue.

Maybe... business project(dll) is targeting 3.5 which affects the loading dlls from shared storage?

Many thanks for your effect, waiting a fix ...

Per: You got mail.

A temporary fix:

in file

\umbraco-74794\releases\umbraco 4.5\umbraco\businesslogic\Utils\TypeResolver.cs

add namespace:

using System.Security;
using System.Security.Permissions;

and change:

sandbox = AppDomain.CreateDomain("Sandbox", AppDomain.CurrentDomain.Evidence, domainSetup);

to
                PermissionSet trustedLoadFromRemoteSourceGrantSet = new PermissionSet(PermissionState.Unrestricted);
                sandbox = AppDomain.CreateDomain("Sandbox", AppDomain.CurrentDomain.Evidence, domainSetup, trustedLoadFromRemoteSourceGrantSet);

DCH, this fix won't help if you are running in full trust?

/Jonas

@Umbraco Core.
have you guy´s been able to replicate this issue yet?

@Jonas,

It works in full trust as I tested, the setting in web config which indicate it to 'loadremoteassembly' is not picked up by Umbraco for some reason.

The above code force it to load remote assebly, thus give us the tree.

As in my enviroment, the above temporary fix does work. (without it no tree, with it you have tree of the nodes)

Yes, it worked on full trust, great!

/Jonas

Great mine is also working after this code change,thanks.

/M

@jonas and @mike, do you have it working with us(binero)?
If that's the case, can you please email me the updated DLL's and I'll create a oneclick package for our controlpanel of it, got the same problem at my test installation http://umbraco.aleborg.me

Email me at anders @ binero.se

@jonas and @mike, btw, you need to change your sessionstate according to this:
https://support.binero.se/index.php?_m=knowledgebase&_a=viewarticle&kbarticleid=105

Can anyone send me the fix please? rik [ at ) orbitone.com

DCH: the source doesn't compile for me when i try to make the suggested changes:

@Rik,

From the error, it seems that you forget to add namespaces

please try add namespace as stated in my previous post:
using System.Security;
using System.Security.Permissions;

and have another try :)

@DCH

Hi DCH and all others,

Is this confirmed, that you just need the changed DLL-file? Could you please send it to me by email niclas [a] vaken [dot] net, as we're interested in trying the product but can't get it running on our Binero account! Any help would be much appreciated.

Thanks

Niclas Lindqvist

I do not recommend you use the temporary fix in production environment, I am still testing to see if it breaks some other things.

Btw, the source you should use is the 4.1.0 branch, not the one in trunk, according to:

http://our.umbraco.org/forum/developers/extending-umbraco/10918-Where%27s-umbracopresentationLiveEditingCanvasClientDependencyProvider-in-the-45-source

so it is somewhere like:

C:\umbraco-73913\branches\4.1.0\

Hi guys,

@Rik Helsen was nice enough to send me a version of businesslogic.dll, which was originally sent by @Anders Aleborg, where the empty-node-tree-bug was fixed. But it seems something else has happened in this version.. Or maybe I'm just not getting something.

If I publish a page and try to view it, or if I preview a page, I always end up with this error message (Debug mode on)

Server Error in '/new' Application.

Method not found: 'System.String 
umbraco.IO.IOHelper.ResolveUrlsFromTextString(System.String)'.
Description: An unhandled exception occurred during 
the execution of the current web request. Please review the stack trace for more information about the error and where it originated in the 
code.

Exception Details: System.MissingMethodException: 
Method not found: 'System.String 
umbraco.IO.IOHelper.ResolveUrlsFromTextString(System.String)'.

Full stack trace can be posted if requested.

If anyone has an idea whether this occurs only with the fixed dll or if it's common, please get back to me. Even better, if someone can tell me what's wrong and/or how to fix it, I'd be delighted!

Regards

Niclas Lindqvist

EDIT: Oh right, I've installed the Creative Website Starter 2.0.3 pack, and that's all i've tried so far, so that might be part of this.

Strange... IOHelper is part of ... businesslogic

maybe other dll is not compiled at same time? (It seems that umbraco release has combine some dlls together...)

I have just compile them, and put all dlls here, you could try it if you like

http://hotfile.com/dl/63129806/01c88d8/bin.zip.html

@DHC

Hi,

I downloaded the files and uploaded to the hotell, but now it seems your compilation was for the 4.5.1 .NET 3.5 version, is that right? (see error message below) I'm trying to rund the NET 4.0 version.. Is it a big job to compile for 4.0? It would help me a lot.

Thanks

Niclas

The value for the 'compilerVersion' attribute in the 
provider options must be 'v4.0' or later if you are compiling for 
version 4.0 or later of the .NET Framework. To compile this Web 
application for version 3.5 or earlier of the .NET Framework, remove the
 'targetFramework' attribute from the <compilation> element of the
 Web.config file.

yes, i double checked, it is default to 3.5

strange it works fine on my IIS based on Windows 7

anyway, i have recompiled it targeting .net4

(only presentation is changed to targeting .net4, businesslogic is still targeting .net 3.5, as change that to .net 4 brings in a lot of compiling error)

hope it works for you:

http://hotfile.com/dl/63370334/b3f103b/umbraco-bin.zip.html

Oh my god you saved my life!

This works perfect! We're running it at Binero 2.0, using ASP.NET 4.0 full trust.

I strongly recommend DCH's fix for anyone trying to run Umbraco 4.5.1 on Binero 2.0 and therefor probably other shared hosting solutions

Thanks @DCH, BIGUP!

Hi all,

I'm also hosting one of my sites on Binero and I think I got the same problem as described in this thread. However, DCH's fix doesn't do the trick for me. This is what my admin looks like:

Nothing happens when any of the buttons/links (i.e. [Create...], [Logout: Administrator], Content, Developer etc...) on this page is being clicked.

I'm very thankful for any kind of help :)

//Magnus

Hmmm, maybe I'm not having the same problem after all. I just tried browsing the adminpage with Internet Explorer (8) and I'm getting these errors (Javascript?!?):

Detaljerad information om felet på webbsidan

Message: 'uiKeys' is undefined.
Row: 259
Chars: 17
Code: 0
URI: http://www.ampmodeling.com/umbraco/


Message: 'UmbClientMgr.uiKeys().defaultdialogs_confirmlogout' are null or not an object
Row: 22
Chars: 111
Code: 0
URI: http://www.ampmodeling.com/umbraco/DependencyHandler.axd?s=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&t=Javascript&cdv=1

Strange...

Hi again :)

I actually think I got it working now and it seems that I didn't have the same problem as described in this file. Sorry for shouting: "WOLF!" ;)

I deleted all files uploaded to my host, deleted the database and created a new one. Then I set the transmissionmethod to "Binary" in my ftpclient (FileZilla) and uploaded the files again (including DCH's fix). And...everything works like a charm :)

//M

This was the correct fix along with an update to /umbraco/js/language.aspx which renders all the translated ui labels and we've tested this at Binero as well (thanks for the test account!).

Thanks for the feedback everyone - v4.5.2 is coming very soon!

Have just downloaded to .NET 4 beta, and it works like a charme, in relation to this problem at least :)

Hi all, we just released a beta of 4.5.2 - which should include a fix for the issue that started this thread (conflict loading assemblies from a remote share in .NET 4) - it's in beta at the moment and we're hoping for feedbcak so we can release it ASAP, if you have time please feel free to check it out

http://umbraco.org/blog/2010/8/24/umbraco-452-beta-is-out

The release-version of 4.5.2 installs like a charm at Binero :)

Great work guys!

I spend hours on a similar problem on deploying a solution hosted at "discount asp.net". I was deploying umbraco v 4.5.2 (Assembly version: 1.0.3891.20719) No content tree and no errors.

What solved my problem was setting "Application Pool Pipeline Mode: " to integrated instead og Classic. The only difference on these 2 modes as I could see was that the content tree was empty in Umraco backend, if i chose classic. Damn :(

I hope my time spend can be helpfull to someone else :)

We just made 4.5.2 website public (http://www.aviapartner.aero) that didn't work on our servers before this bugfix)

Looks like the new version is the one to go for.

I am running 4.5.2 (.NET 3.5) in shared hosting - but my tree nodes are still empty. I have tried the reconfigure path to ClientDependency and updating access to app_data folder but nothing works :(

Running the site localhost works perfectly.

I too am trying, and failing to get this working on Shared Hosting at blacknight.ie

I have 4.5.2 (.NET 3.5), runs OK on my server at home, but not at Blacknight.  Can anyone tell me exactly what questions to ask Blacknight in order to ascertain if there is a configuration issue?  I have checked permissions, the front-end site works fine..  Please help me

Waiting patiently :)

same problem, umbraco 4.7.0.378 - 4th day of trying to resolve this. I've tried all suggestions from this post with no luck. The only 'error' I'm getting is
"[UmbracoExamine] An error occurred recreating the index set,Request failed., IndexSet: InternalIndexSet"
But I doubt that it has anything to do with missing nodes.

Trying to run in medium trust. Installer (after a few modifications in web.config - described below) run without any errors or warnings. Fresh install, no startups included.
Unblocked the assembly (though that was for the second time I installed umbraco - I don't have access to IIS to restart it, I can only restart my app by modyfying the web.config)

The TreeDataService.ashx returns an empty array, no errors, no signs of permission mismatch, all requests are OK (literally - http response code 200)

Changed web config:
  <add key="umbracoUseMediumTrust" value="true" />
added
  requirePermission="false"
to clientDependency, Examine and ExamineLuceneIndexSets sections (there were errors in the log table when this was not set)

Any ideas on how to get this running?

Getting exactly the same problem as Krzysiek - just installed a fresh 4.7 on a dev box (Server 2003) to test out medium trust operation; same modifications as above - I get the trees if in full trust, as soon as I add  they vanish. Same response from TreeDataService.ashx (although I don't know if it requires parameters to return anythign useful?).

I am finding it a tad frustrating that there is the core umbracoUseMediumTrust option that implies it should work in medium trust and I just can't get it to do it! :o/

EDIT: Actually, I'm not even getting any Examine errors.

I am getting no unhandled exceptions and nothing in either the system event viewer or the umbracoLog table, incidentally, and umbDebugShowTrace=true doesn't seem to have any effect in the backend, so I'm kind of at a dead end.

Interestingly, TreeDataService.ashx fails completely in High Trust, even with umbracoUseMediumTrust  enabled:

[SecurityException: Request for the permission of type 'System.Security.Permissions.SecurityPermission, mscorlib, Version=4.0.0.0, Culture=neutral, PublicKeyToken=b77a5c561934e089' failed.]
   System.AppDomain.get_Evidence() +24
   umbraco.BusinessLogic.Utils.TypeResolver.GetAssignablesFromType(String[] files) +924
   umbraco.BusinessLogic.Utils.TypeResolver.GetAssignablesFromType(String path, String filePattern) +200
   umbraco.BusinessLogic.Utils.TypeFinder.FindClassesOfType(Boolean useSeperateAppDomain, Boolean onlyConcreteClasses) +123
   umbraco.BusinessLogic.Application.RegisterIApplications() +72
   umbraco.BusinessLogic.Application..cctor() +40

is working on a reply...