Want to clear an existing signature and add a new one. Don't see "clear singature" right click

[Karma5F91]

I'm trying to clear an existing signature and add a new one.  I used to be able to right click to select "clear signature" option.  However, I don't see the "clear singature" option.

Can anyone help?  I am using the Adobe Acrobat Reader DC Version 2021.007.20099.  I'm on Windows 10. Thanks.

[Bernd Alheit]

Have you signed the document?

[Karma5F91]

Yes.  I have digitally signed the document.   I would like to clear this and add new signature. 

[Bernd Alheit]

Repair the installation of Acrobat Reader.

[lrwillsonqamanager]

Same problem - I repaired per the "help" instructions - when I click "Sign yourself" and click the "+" to add a signature, I get a BLACK popup window that does nothing.  I can click "Esc" to get back to the file, but can never add a signature.