Don't do Reset PRAM on a patched Mac running an unsupported MacOS with OCLP!!!

I had an issue with iMovie and the graphics card on my Mac mini 3,1 running Big Sur via OCLP and thought by doing Reset PRAM could fix the problem. Big mistake! After resetting PRAM my Mac could not boot anymore neither from the disk nor from the OCLP USB installer. It was always stuck in the beginning of the Apple logo and couldn't go any further that that, not able to boot the operating system, not for doing a new fresh installation, not even possible to run disk utility.

Solution: I had to create a new installation USB on another Mac with the latest supported OS (OSX El Capitan in my case). By pressing option key on the boot I selected this El Capitan USB installation an finally the Apple logo could progress further. Then I selected disc utility and run first aid for the MacOS hard disk. After that I restarted the system and this time I selected the OCLP patch in the boot menu and then the unsupported OS from the hard disk and BOOM!!! Finally the Apple logo could load till the end!