I've been having a problem with technic launcher on my niece's computer, on which I had installed it.
I encountered a lot of problems
Firstly, there was different error, after hours of trying everything what I could find (updating drivers, clearing PATH in enviroment for java and reinstalling it), I found a fix on reddit:
in .technic\modpacks\tekkitmain\config\bspkrsCore.cfg to false
This resulted in game opening and working, but when I created and opened a world, I couldn't see anything (possibly optifine draw distance setting,