After a failed upgrade from Citrix VCAD 7.15.3000 to 1912, uninstalling 7.15 and reinstalling 1912, a VDA was rendered useless. I couldn’t start the published desktop or finance applications. It was the only VDA in a Machine Catalog (provisioning manual), showed as registered and added to a dedicated Delivery Group. The Delivery Group showed one registered machine and one missing registration (which is odd with only one VDA in the Machine Catalog).
Removing the VDA from the Machine Catalog, restarting it and adding it back in, resulted in the same warning as shown above. Completely removing the Machine Catalog and Delivery Group and rebuilding it resulted in the same warning as well (even using different names). In Director this VDA was shown as a failed Multi Session OS with Maximum Load.
I looked into the 100% load evaluator warning, found some Perflib and WMI errors in the eventviewer and decided to rebuild the performance counters with the ‘LODCTR /R’ command. The first try resulted in an error code is 2. The second try was successful.
After this the warning in the Citrix Studio Delivery Group disappeared and the the VDA returned to active state and users could start published applications and published Desktop again.