Hope you are doing well and sorry for the trouble.
Would you mind sharing the version of the Adobe Acrobat /Reader DC you are using? To check the version go to Help > About Acrobat and make sure you have the application updated to version 21.05.20048 Go to Help > Check for updates and reboot the computer.
Acrobat now has a new cryptography library - SafeLogic CryptoComply, for digital signatures and protection. The library is enabled by default. However, if you want to use the old library - Dell BSAFE, follow the steps below to disable the new library.
1. In Acrobat, go to Edit > Preferences (Windows), or Acrobat > Preferences (macOS).
2. In the categories on the left, choose Security, and then deselect the option Use SafeLogic CryptoComply.
Note: This feature is being rolled out incrementally and may not be available to all users.
You may also checkout the similar discussions listed below and see if that helps: