I try to play the FTB Academy modpack using MultiMC 5 (ver 0.6.8-1419 on win32). It works fine up until it has to load Astral Sorcery, where it stops and gives me this error report: https://paste.dimdev.org/liwogiziko.mccrash

Any help to fix this would be greatly appreciated.

That's the problem, all good now, thanks!

Not AS issue. It calls out that you don't have enough memory allocated in the beginning of the trace. 1 gb allocated is about 30% of what any modded pack should have allocated in 1.12. Push it to 3 gb and try again.