I have two MacBook Pros, newer and older. Both use the same KeyChain, synched by Apple. On the old MacBook Pro I have an old Adobe Acrobat 9 Pro (version 9.5.5). On the newer MacBook Pro, I have recently installed Creative Cloud's Adobe Acrobat Pro DC. I am able to use my digital signature on my old MacBook Pro with Acrobat 9 Pro. To do that, Acrobat knows where my signature file is, and I use my password from my KeyChain for the "Adobe Acrobat Digital Signature" file. However, when I try to apply a digital signature on the newer MacBook Pro with Acrobat Pro DC, it doesn't find my signature file. Furthermore, when I look in my KeyChain on the newer MacBook Pro, I cannot find the "Adobe Acrobat Digital Signature" file. This is odd, since the KeyChain is typically synched across my two MacBook Pros. This was not a problem before installing Adobe Acrobat Pro DC on the newer MacBook Pro. So, I assume that during the installation, it somehow deleted my older "Adobe Acrobat Digital Signature" file. How can I share my signature file across the two MacBook Pros, and the two different versions of Acrobat Pro?
Hope you are doing well and sorry for the trouble. As described, you are unable to digitally sign as the "Adobe Acrobat Digital Signature" file disappeared from Mac KeyChain after installing Acrobat Pro DC
Would you mind sharing the version of the Adobe Acrobat DC you are using. To check the version go to Help > About Acrobat and make sure you have the latest version 21.05.20048 installed. Go to Help > Check for Updates