PageFlow Application Block throwing exception

Jan 2, 2008 at 9:42 PM
I'm getting the following exception in a production environment. The application runs fine for multiple hours then gets into a state where every request is generating the following error. Any thoughts? Could there be a threading issue with the WorkflowDataAdapter class?

Event Type: Error
Event Source: qqq application
Event Category: None
Date: 1/2/2008
Time: 3:13:19 PM
User: N/A
Computer: PRS-qqq
Description:
MESSAGE: The given key was not present in the dictionary.
SOURCE: mscorlib
Data:
FORM: _LASTFOCUS=&_EVENTTARGET=&_EVENTARGUMENT=&_VIEWSTATE=%2fwEPDwULLTE5MjA1NDg1NDAPZBYCZg9kFgICAQ9kFgQCBQ9kFgICAQ9kFgQCAQ8PFgYeBFRleHQFQ0hvdyBkaWQgeW91IHJlY2VpdmUgeW91ciBib2fQ9UmewQFNNvCqQpjz9NXr%2b
URL: http://www.sample.com/AppPage.aspx
QUERYSTRING:
STACKTRACE: at System.ThrowHelper.ThrowKeyNotFoundException()
at System.Collections.Generic.Dictionary`2.get_Item(TKey key)
at Microsoft.Practices.PageFlow.WorkflowFoundation.WorkflowDataAdapter.GetData(Guid instanceId) in C:\devtools\samples\WCSF Source\Blocks\PageFlow\Source\PageFlow.WorkflowFoundation\WorkflowDataAdapter.cs:line 105
at Microsoft.Practices.PageFlow.WorkflowFoundation.WorkflowFoundationPageFlowState.Get(String key) in C:\devtools\samples\WCSF Source\Blocks\PageFlow\Source\PageFlow.WorkflowFoundation\WorkflowFoundationPageFlowState.cs:line 121
at Microsoft.Practices.PageFlow.WorkflowFoundation.WorkflowFoundationPageFlowState.Contains(String key) in C:\devtools\samples\WCSF Source\Blocks\PageFlow\Source\PageFlow.WorkflowFoundation\WorkflowFoundationPageFlowState.cs:line 101
at Microsoft.Practices.PageFlow.WorkflowFoundation.WorkflowFoundationPageFlowState.get_Item(String key) in C:\devtools\samples\WCSF Source\Blocks\PageFlow\Source\PageFlow.WorkflowFoundation\WorkflowFoundationPageFlowState.cs:line 76
at Microsoft.Practices.PageFlow.WorkflowFoundation.WorkflowFoundationPageFlow.get_Status() in C:\devtools\samples\WCSF Source\Blocks\PageFlow\Source\PageFlow.WorkflowFoundation\WorkflowFoundationPageFlow.cs:line 134
at Survey.Web.SurveyTemplate.btnNext_Click(Object sender, EventArgs e) in C:\projects\pearson\Net Survey\Source\Survey.Web\SurveyTemplate.Master.cs:line 46
at System.Web.UI.WebControls.Button.OnClick(EventArgs e)
at System.Web.UI.WebControls.Button.RaisePostBackEvent(String eventArgument)
at System.Web.UI.WebControls.Button.System.Web.UI.IPostBackEventHandler.RaisePostBackEvent(String eventArgument)
at System.Web.UI.Page.RaisePostBackEvent(IPostBackEventHandler sourceControl, String eventArgument)
at System.Web.UI.Page.RaisePostBackEvent(NameValueCollection postData)
at System.Web.UI.Page.ProcessRequestMain(Boolean includeStagesBeforeAsyncPoint, Boolean includeStagesAfterAsyncPoint)

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Any help or suggestions would be greatly appreciated.