Unable to sign a document

[timothy_8433]

When I try to sign a document I get the following error message: "The operation failed because Adobe Acrobat encountered an unknown error."

I have tried shutting down and restarting the app multiple times.  I have rebooted my computer multiple times.  I have updated the app and rebooted my computer.  

Help!

[creative explorer · Accepted solution]

@timothy_8433 wow, you have done a few things already that I was about to suggest (ie restarting, updating and re-installing the app)! 

First question is....do you have the right application that allows you to sign. The 'free' version of Acrobat won't let you sign, only the paid versions can.

If you have the paid version, I have a feeling, it might be corrupted preferences. I know I had recently removed my applications preferences (over 2 gigs of it!) and since then, all the issues I had went away! To address this, first, try clearing Adobe Acrobat's preferences by navigating to ~/Library/Preferences/ and deleting any files that start with "com.adobe.Acrobat." Don't worry, when you do a restart, it should start to create new ones. (I just looked at my preferences, its at 355kb!) Then, ensure your macOS keychain is functioning correctly by opening Keychain Access and running First Aid. If the issue persists, verify file permissions by right-clicking the document, selecting "Get Info," and ensuring your user account has read and write access.

[creative explorer · Accepted solution]

@timothy_8433 wow, you have done a few things already that I was about to suggest (ie restarting, updating and re-installing the app)! 

First question is....do you have the right application that allows you to sign. The 'free' version of Acrobat won't let you sign, only the paid versions can.

If you have the paid version, I have a feeling, it might be corrupted preferences. I know I had recently removed my applications preferences (over 2 gigs of it!) and since then, all the issues I had went away! To address this, first, try clearing Adobe Acrobat's preferences by navigating to ~/Library/Preferences/ and deleting any files that start with "com.adobe.Acrobat." Don't worry, when you do a restart, it should start to create new ones. (I just looked at my preferences, its at 355kb!) Then, ensure your macOS keychain is functioning correctly by opening Keychain Access and running First Aid. If the issue persists, verify file permissions by right-clicking the document, selecting "Get Info," and ensuring your user account has read and write access.

[AnandSri · Accepted solution]

Hello!

I hope you're doing well, and we apologize for the delayed response and the trouble.

Please ensure you have the latest version of Acrobat installed on the machine: 25.001.2043x. Optional update, Mar 19, 2025. Check for any pending updates from the Menu > help > check for updates, install the updates, restart the app and the machine, and check. For more information, see this: https://adobe.ly/42jgGYB

Do you get the error when using the desktop version or online services? Open the PDF and go to File > Properties > Security. Ensure that signing is allowed. If not, you may need to supply the permission password to change the settings. Ensure your digital ID is correctly set up. Go to Edit > Preferences > Signatures > Identities & Trusted Certificates > Moreand verify your digital ID. See this article for more information: Manage Digital IDs in Acrobat

Let us know how it goes after trying the above suggestions, and from our community expert.

Thanks,

Anand Sri.