Getting the following error, really appreciate any insights. I am using cassini, but i don't think thats the issue as its work outside of umbraco.

The state information is invalid for this page and might be corrupted.

Here's whats happening.

[b]Map.aspx ( has gmap on it )
[/b]
Has the following js

[quote]new Ajax.Updater('display', 'flagform.aspx?lat=' + lat + '&lng=' + lng + '&zoom=' + zoom, { method: 'get' });
}
[/quote]

[b]
flagform.aspx[/b]

[quote]<%@ Master Language="C#" MasterPageFile="~/umbraco/masterpages/default.master" AutoEventWireup="true" %>

[/quote]


All is good so far, when the user clicks on the map the js function is called and flagform.aspx and loads the marco FlagForm.

[quote] protected void ButtonSendClick(object sender, EventArgs e)
{
// etc...
}[/quote]

However when i try and submit the form I get the following error.

The state information is invalid for this page and might be corrupted.


[FormatException: Invalid character in a Base-64 string.]
System.Convert.FromBase64String(String s) +0
System.Web.UI.ObjectStateFormatter.Deserialize(String inputString) +77
System.Web.UI.ObjectStateFormatter.System.Web.UI.IStateFormatter.Deserialize(String serializedState) +5
System.Web.UI.Util.DeserializeWithAssert(IStateFormatter formatter, String serializedState) +37
System.Web.UI.HiddenFieldPageStatePersister.Load() +116

[ViewStateException: Invalid viewstate.
Client IP: 127.0.0.1
Port:
User-Agent: Mozilla/5.0 (Windows; U; Windows NT 5.1; en-GB; rv:1.9.0.8) Gecko/2009032609 Firefox/3.0.8 GTB5 (.NET CLR 3.5.30729)
ViewState: /wEPDwUENTM4MWRk8m/cHOHOORDfE5NQATRv4z0msqI=,/wEPDwUENTM4MWQYAQUeX19Db250cm9sc1JlcXVpcmVQb3N0QmFja0tleV9fFgIFPmN0bDAwJGN0bDAwJENvbnRlbnRQbGFjZUhvbGRlckRlZmF1bHQkRmxhZ0Zvcm1fMSRDaGVja0JveE9wdEluBUdjdGwwMCRjdGwwMCRDb250ZW50UGxhY2VIb2xkZXJEZWZhdWx0JEZsYWdGb3JtXzEkQ2hlY2tCb3hEYXRhUHJvdGVjdGlvbp+IekRE0JkasBbw57LIrNHIFt23
Referer: http://localhost:3032/maps/map1.aspx
Path: /maps/map1.aspx]

[HttpException (0x80004005): The state information is invalid for this page and might be corrupted.]
System.Web.UI.ViewStateException.ThrowError(Exception inner, String persistedState, String errorPageMessage, Boolean macValidationError) +118
System.Web.UI.ViewStateException.ThrowViewStateError(Exception inner, String persistedState) +13
System.Web.UI.HiddenFieldPageStatePersister.Load() +221
System.Web.UI.Page.LoadPageStateFromPersistenceMedium() +107
System.Web.UI.Page.LoadAllState() +43
System.Web.UI.Page.ProcessRequestMain(Boolean includeStagesBeforeAsyncPoint, Boolean includeStagesAfterAsyncPoint) +5181
System.Web.UI.Page.ProcessRequest(Boolean includeStagesBeforeAsyncPoint, Boolean includeStagesAfterAsyncPoint) +247
System.Web.UI.Page.ProcessRequest() +79
System.Web.UI.Page.ProcessRequestWithNoAssert(HttpContext context) +23
System.Web.UI.Page.ProcessRequest(HttpContext context) +110
ASP.defaultaspx.ProcessRequest(HttpContext context) in c:\WINDOWS\Microsoft.NET\Framework\v2.0.50727\Temporary ASP.NET Files\root\639cfdb4\de75c345\AppWebdefault.aspx.cdcab7d2.dlfi6nzk.0.cs:0
System.Web.CallHandlerExecutionStep.System.Web.HttpApplication.IExecutionStep.Execute() +391
System.Web.HttpApplication.ExecuteStep(IExecutionStep step, Boolean& completedSynchronously) +76