Error message when adding a new column:

Culture ID 1164 (0x048C) is not a supported culture.
Parameter name: culture

The file "Microsoft.SharePoint.ApplicationPages.dll" has not been updated in the app_bin folders for each virtual server.

1. Stop the IIS service.
2. Copy the file from 12Hive\Config\Bin to all app_bin which have SP installed
3. The version of the file "Microsoft.SharePoint.ApplicationPages.dll" should be "12.0.6548.5000"
4. Start the IIS service again.