SYMPTOM:
When upgrading a project, the following error is thrown and the upgrade process is interrupted:

The 'Managed Objects' folder cannot be saved, moved, copied or deleted. Item 'Drop Table Method' cannot be found. This deprecated privilege 'DSSPrivilegesReserved' cannot be added to a user or user group...
Internal Error: Update prompt styls failed in loading WebProperties::WebPromptAvailableStyles value from the project object