In addition to the KBs, product documentation has a procedure for recovery
Usually there's no valuable long term data in mNode, so you can simply re-deploy HCC (Management Service) if VM is still viable.
If VM isn't viable, you can redeploy the VM using mNode OVA, and then deploy HCC.
If your mNode is not allowed to get out to the Internet, you would have to download mNode and Management Services archive file (this would be uploaded to mNode before completing deployment).
You can find a list of Management Services releases and links to their release notes at
As @Ontapforrum said, it's a good idea to get someone from Support booked for a Web meeting when you go to do this, if you haven't done it before.