a fresh install of the plugin under OMV4 and a new generated VM, the start ends imidiatly with the error "The virtual machine 'Test' has terminated unexpectedly during startup with exit code 1 (0x1)" Can someone help me??
There's not enough info to even guess. I mean, the OS you're trying to start could have been loaded from a corrupted disk - the OS may not be suited to run on your virtualized hardware, etc., etc., etc. Running a guest operating system, using software to spoof the OS into believing it's running on hardware, brings with it a near endless set of potential issues.
Download something simple, that's designed to be highly compatible, like Knoppix or Puppy Linux and try to set one of them up. See what happens. If you're not familiar with VB, try loading VB on a Windows machine to get more familiar with it.