Hello,
This issue was related to XPC-ng and caused me to delete and recreate and configure one of the most important virtual machines I have. As I said, every virtual machine I create is only 33% complete, and when I try to turn on virtual machines that are already turned off, I get the message "VM state is halted but should be running".
I had to turn the server off and back on to fix the problem. To be honest, I'm afraid to test again to see if the problem is fixed, because I have a VPN server that has a number of users connected to it, and I also have a monitoring server.
If it is a hardware problem, the green lights on the hard drive should change to orange or red, but all the hard drive lights on the server are green. I think the problem is related to the stability of XCP-ng.