After updating Adobe Reader DC on our XenApp 7.15 environment we started seeing the acrord32.exe generating a high amount of CPU usage, causing performance issues for the end-users.
A quick fix was to kill all the acrord32.exe processes that were stuck running in the background, but we couldn’t reproduce the issue with a test account so troubleshooting this turned out to be a bit of a hassle.
It turned out that when starting Adobe Reader, it tries to find the following registry key:
[HKCU\SOFTWARE\Microsoft\Windows\CurrentVersion\Themes\Personalize]
We were able to confirm this with Sysinternals’ process monitor, in this case the problem didn’t occur because Adobe was able to find the registry key:
If this key doesn’t exist, the process will be stuck in the background using up to 25% CPU per instance.
We created a new action in WEM and pushed the registry key to our users, this solved the problem.
This issue occurs in the following versions of Adobe Reader DC:
2019.021.20047
2019.021.20048