This also worked for us, thanks for the tip.
We run Horizon 7.4 with vCenter 6.5u1 in a cloud pod architectures (2 pods/2 sites) with a vCenter in each site.
What we did to fix the issue:
- Disconnect/sign out all the sessions.
- shut down all connection servers of both sites.
- Reboot the vCenters in both sites (we run them in VCHA pairs):
- shut down passive node
- shut down active node
- shut down witnes
- Power on in any order
- power on all connection servers (maybe it changed in newer version but 1 by 1 did not work).
- Wait for horizon to delete/create vm...
- Run viewdbcheck.cmd on a connection server of each site to clean the error VMs.
After that everything went back to normal. We still had a few error VMs in horizon that are not in vcenter. You can either remove them in the ADAM database or wait for them to get cleaned over time.
