It appears that it is a graphics issue. I tried it in safe mode and it worked then tried low resolution video mode and it also worked on that. I still don’t understand why my previous version doesn’t work properly or know what to do now.
What graphics adapter or card do you have? Even on this system which has ancient Intel onboard graphics, Vital 1.5.5 will work and on my studio system it works fine with a GTX 1050ti.
My internet system has Intel HD Graphics 2500 so Vital should work on your system.
I could be wrong but I seem to remember seeing other people reporting issues that were also running Win 11 but don’t quote me on that as my memory may be failing me.
Did you say the Standalone won’t work on your Win 11 system either? If not that would tend to point away from it being FL Studio as the cause.
Did you try posting at the FL Studio forums just to see what they say?
Are you using the VST 2 or VST 3 version of Vital? I recommend using the VST 2 version in FL Studio at least.