Yes, it was a memory Error in another thread. The error came on line 129:
out = net(valInp) # [:50]
RuntimeError: [enforce fail at ..\c10\core\CPUAllocator.cpp:73] data. DefaultCPUAllocator: not enough memory: you tried to allocate 40960000 bytes. Buy new RAM!

with lower batch sizes it didnt crash, but i couldnt figure out what causes problem 2.