Had the same issue as soon as I upgraded to 7.2 I got first a missing license file and corrupted USB drive which was not the real problem, anyway I migrated to another usb drive then I got this issue. Your posts helped me troubleshoot and finally fix it, last post from XILENCE was the tipping point, the only difference I copied all content of "Plugins" folder and copied also the network.cfg. Finally got the "Main" page working. Thank you all!!
UnRaid newbie here, can you explain how to activate the proxmox agent in Unraid, I have it running in a VM on proxmox, everything works perfectly fine except for the guest agent, it is enabled on the VM, but it shows as not running on the Summary, I am on the latest Proxmox and UnRaid 6.11.5