Unable to generate a temporary class (result=1). error CS2001: Source file ‘C:\WINDOWS\TEMP\bbptmpxs.0.cs’ could not be found error CS2008: No inputs specified
The above error occurs when the Reporting Services service account doesn't have permissions on the Temp folder in system drive. To resolve this issue, grant List Folder Contents and Read permissions to the service account on the C:\WINDOWS\TEMP folder. Reporting Services creates temporary files in this folder when the reports are accessed using Report Manager. Please note that the file name might be different each time you access the reports.
This solution is described in the KB article here - http://support.microsoft.com/kb/908158