Report Server rsInternalError Error

When accessing all the TFS reports from report server, the following message showed up in browser.
An internal error occurred on the report server. See the error log for more details. (rsInternalError)

Further investigation found more information in the Reporting Service log file and dump log file.

ERROR , SQLDUMPER_UNKNOWN_APP.EXE, AdjustTokenPrivileges () failed (00000514)

w3wp!processing!5!06/07/2010-08:48:03:: a ASSERT: Assertion failed! Call stack:
Microsoft.ReportingServices.ReportProcessing.Persistence.IntermediateFormatReader.Assert(Boolean condition)
Microsoft.ReportingServices.ReportProcessing.Persistence.IntermediateFormatReader.Initialize(Stream stream)
Microsoft.ReportingServices.ReportProcessing.Persistence.IntermediateFormatReader..ctor(Stream stream)
Microsoft.ReportingServices.ReportProcessing.ReportProcessing.DeserializeReport(GetReportChunk getChunkCallback, ReportItem parent, Hashtable& definitionObjects)

These reports used to work, and there was no known changes to the system. I do notice that the size of chunkData table in the reportserver database became 0 around the same time the problem started.

To solve the problem, we need to restore the reports. From SQL Server Management Studio, run

use reportserver
go

SELECT
itemID, Path, Name, CAST(CAST(Content AS varbinary(max)) AS xml) ReportXML
FROM
dbo.Catalog
where content is not null

The ReportXML column is the report definition. Save it to a name.rdl file, and upload the file to the report site to overwrite the report.

This can not be the best solution, as I have 900+ reports to recover. But it is the only working one I found so far.