Impossible to update a Machine Catalog, receiving the following error: "Unable to retrieve properties of an object because it does not exist. The object 'vimVirtualMachine:vm-XXXXXX' has already been deleted or has not been completely created."

• This might happen if, the master image concerned was moved to a different storage, and back to the original.
• Creating a new machine catalog from a new hosting connection pointing to the same affected master image doesn't cause the issue

1. Restart Hosting Service on all Delivery Controllers on the site. Then, stop it on all of them, except the one you are running Studio from.
2. Check the State of the Hosting Connection(s) available on the site with the following Powershell command on a Delivery Controller:
   • asnp Citrix*
   • Get-BrokerHypervisorConnection | fl name, HypHypervisorConnectionUid, state

3. Any resource showing "Unavailable" could be the issue. To force a refresh, run this powershell command on the Delivery Controller. (It is recommended to run this command outside of business hours)  :
   • Reset-BrokerHypervisorConnection -HypHypervisorConnectionUid <Affected_UID>
4. Restart the Host Service on the Delivery Controller.
5. Check the status again. The hosting connection State should be back to "On"