Try steps in order until issue is resolved.

1. Restart IIS
2. Repair install of workstation from Deploy folder
3. Repair install of FAWEB
4. Verify that ODBC can connect (May need to contact Blackbaud Support if using Mixed Mode in SQL Server)
5. Update to the latest version of Education Edge and FAWEB
6. Verify the web.config is configured correctly. Refer to How to configure web.config for Integrated Windows Authentication (BB147746) for instructions.