I hope this thread hasn't already been posted. I ran into this problem today. I could find fine how to resolved the issue. I reinstalled my proxmox server thinking it would clear the problem. Once I rebooted the server, the problem remained. I have a Proxmox Backup server installed on an ssd. I boot to the pbs, the same error show up in the boot cycle. Has anyone had this problem, if so how was it resolved.