Hi,

using umbraco 6.1.6

after nog using the backend of our umbraco website for a few months I started developing for our website again. As the website was being used by some people, I decided to use a staging environment. So I moved all my files and finally got the database also cloned.

But now whenever I try to login to the backend of umbraco (in the live and the staging environment) I get a javascript error in my firebug console:

{"Message":"The user has no umbraco contextid - try logging in","StackTrace":"   at Umbraco.Web.Security.WebSecurity.ValidateCurrentUser(HttpContextBase httpContext, Boolean throwExceptions)\r\n   at Umbraco.Web.Security.WebSecurity.AuthorizeRequest(HttpContextBase httpContext, Boolean throwExceptions)\r\n   at Umbraco.Web.WebServices.UmbracoAuthorizedWebService.AuthorizeRequest(Boolean throwExceptions)\r\n   at Umbraco.Web.WebServices.UmbracoAuthorizedWebService.AuthorizeRequest(String app, Boolean throwExceptions)\r\n   at umbraco.presentation.webservices.TreeClientService.GetInitAppTreeData(String app, String treeType, Boolean showContextMenu, Boolean isDialog, TreeDialogModes dialogMode, String functionToCall, String nodeKey)","ExceptionType":"System.InvalidOperationException"}

As suggested in other posts, I delete my cookies and try again, but no luck.

I also get some other errors from time to time:

uiKeys is undefined

I uploaded my umbraco/config/lang folder using Binary, but I still get the error sometimes

Validation of viewstate MAC failed. If this application is hosted by a Web Farm or cluster, ensure that configuration specifies the same validationKey and validation algorithm. AutoGenerate cannot be used in a cluster.

I added this to my web.config

<pages enableEventValidation="false" validateRequest="false" viewStateEncryptionMode ="Never" />

and the error seems gone

I have been at this for several hours and can't seem to fix it.

Locally loggin in works.