What is the error message?
Could you please let us know the OS version that you are using? Are you using Adobe Acrobat on Android or iOS?
I am also receiving an error message when trying to download an update to version 4.3 for android. Error 927.
The error is not related to Adobe Acrobat app. There's some issue with the Play Store on your phone. You might try the instructions given at Error 927 Play Store - 3 Ways to Get rid of it in Android | Fix Errors.
Hopefully that should fix your problem.
Adobe Acrobat Team
Thank you for the info which led to success in downloading the app update.