Adobe Acrobat Pro 11 not connecting to scanner

[Paul602]

I have been scanning with my copy of Adobe Acrobat Pro 11 on Windows 10 from my two printer-scanners for many years until recently when it stopped scanning, giving the error that it cannot connect to either of the scanners. The printer-scanners (Brother and HP) are connected to my home network. This issue started after I removed a duplicate installation of the HP printer-scanner from the Windows settings. I guess that the removal of the scanner changed the port settings that Acrobat cannot recognize.

I uninstalled Acrobat and reinstalled it, expecting that it will then recognize the scanners, but it continues to give the same error.

I can scan from those scanners with the Windows Fax and Scan app. So, the scanner drivers are working. I can print PDF documents from Acrobat to those same printer-scanners.

I tried the steps given at https://helpx.adobe.com/acrobat/kb/troubleshoot-scanner-issues-acrobat.html#troubleshoot, but it didn't solve the problem.

A solution will be much appreciated.

[try67]

Acrobat XI is an old and unsupported version, and is no longer compatible with Windows 10, so problems are to be expected. To increase the chances of it working properly make sure you have all updates installed (up to 11.0.23) and run it in Compatibility Mode with an earlier OS, like Windows 7.

Updates are available here:
ftp://ftp.adobe.com/pub/adobe/acrobat/win/11.x/
You must use a dedicated FTP client to open the link, it won't work in most browsers.

[Paul602]

Like I mentioned, I have been using Acrobat XI with Windows 10 for many years without any issue after updating Acrobat XI to all the available updates. I added printer-scanners to my system in the past, and Acrobat XI picked them up without complaining. This is the first time I ran into this situation where Acrobat XI lost its connection to my scanners after I deleted one duplicate addition of a scanner in Window 10's Devices and Printers.

I am hoping someone in the forum may have experienced something similar and found a solution.

[Paul602 · Accepted solution]

Digging through more posts in this forum, I found the solution. It is at Acrobat XI won't recognize scanner  

It required deleting a registry key.