Modelsim #ERROR failed to start simulation kernel

okay.

after 3-4 different versions of model sim installed, trying it on different operating systems and installing modelsim more than 10 different times it, for some reason, started working out of nowhere.

i simulated as i did normally, it threw that error.

then i accidently simulated again at which point it worked. and it now works with a big project.

very strange, i cant pinpoint exactly what i did in the 3 ms of simulating it the second time. how can this even happen, i do not understand, it has me flummoxed.