Source: https://community.adobe.com/t5/acrobat-sdk/adobe-fill-and-sign-how-to-change-add-a-signature/td-p/8333207 I have this problem as well, clicking on the "-" sign next to my already installed signature does nothing. I cannot find a way in Adobe Acrobat DC to get rid of it or replace it. I was able to use the method described here by Peeters31644761 (Thank you!) to delete the signature files in AppData... ``` %appdata%\Adobe\Acrobat\DC\Security\acrobat_fss_signature_initials %appdata%\Adobe\Acrobat\DC\Security\acrobat_fss_signature_initialsi %appdata%\Adobe\Acrobat\DC\Security\acrobat_fss_signature_initialsk ``` And thank you to JimsonC for providing the full path to these files... Located at `C:\Users\\AppData\Roaming\Adobe\Acrobat\DC\Security` [1]: https://community.adobe.com/t5/acrobat-sdk/adobe-fill-and-sign-how-to-change-add-a-signature/td-p/8333207