As per the description above, you are getting the error message of RegSvr32 with Acrobat Standard 11, is that correct?
Please check for any pending updates if possible from Help>Check for updates, and reboot the machine after the installation of updates. Try repairing the installation files from Help>Repair installation(Only for Windows). Reboot the machine and see if this brings any difference.
If the issue still persists, please use the Acrobat cleaner tool to remove Acrobat Download Adobe Reader and Acrobat Cleaner Tool - Adobe Labs Link: https://labs.adobe.com/downloads/acrobatcleaner.html?22
Reboot the machine and install Acrobat Standard 11 from Download Pro or Standard versions of Acrobat DC, 2017, XI, or X
Note: Adobe Acrobat 11 is already declared as end of support, End of support means that Adobe no longer provides technical support, including product and/or security updates, for all derivatives of a product or product version (localized versions, minor upgrades, operating systems, dot and double-dot releases, and connector products).
So above shared solutions may or may not work. For details, information refer to End of support for Adobe Acrobat XI and Reader XI
Let us know how it goes.