Exactly the same issue here. Pretty much the same Versions of Horizon, UEM and Appvol. It seems Users are able to open .pdf files for a while until the "failed to load Core dll" appears. Only a relog seems to help. AR DC is installed on the golden image and not deployed via appstack.
Any help is appreciated
Same issue here. Almost identical setup except Outlook 2016 is in the base image and appvols just handling the OST.
Same here. Office and Reader is installed on the Base Image. Seems to work after deleting the users writable profile but that's not the solution.
I have found that if the user goes to apps & features then modify on acrobat reader then does a quick repair it fixes the issue. A bit annoying as you have to do it for everyone who has the issue but it's the best I've found so far.
We have been plagued by this issue as well for quite sometime, though it was hard to pin down as it was happening to a lot of users but not all.
I finally figured it out.
If you add the Image path name and Command line fields to task manager and launch Adobe Reader, for the users who are getting this issue it will show it launching from their writables volume. However for users that weren't having this issue it was just launching from c:\program files (x86)\Adobe...
I assume that for the people affected at some point an auto-update ran and thus Adobe Reader became virtualized for them causing the failed to load core .dll error.
To fix I added the following lines to the writable snapvol.cfg file to exclude Adobe Reader:
# Adobe Reader
exclude_uwv_file=\Program Files (x86)\Adobe\Acrobat Reader DC
Hope this helps!