If I try to add digital signature in dwg file I get this informal message that "You do not have the right to view, add, or delete digital signatures" or password "You do not have permission to protect files. This permission is controlled by the MS_PROTECTION_ENABLE config variable".
How to add rights or Digital Signatures and Digital Rights are just not supported in DWG files?
There is some info here- Does not say if it applies to DWG files.
Connect r17 10.17.2.61 self-employed-Unpaid Beta tester for Bentley