The application indicates issues with keys
When confidential files are protected for several users, SDS for C&M checks the availability and validity of each user's digital encryption keys, including yourself.
Without a key, you will not be able to protect files or access protected files.

If your key is considered invalid (expired or revoked), you cannot protect files or save changes made to protected files.
You need to contact your System administrator and request the renewal of your key.

If there is an issue with a user's key when you attempt to protect files, a window appears and specifies the issues:
You can choose to continue despite the issues or cancel and go back to the user selection window.
If you continue even though one of the keys is unavailable or considered invalid (expired or revoked), the files will be protected for other users. The user whose key is invalid will not be able to access the files.