memlist :o

When modelling blender often gets stuck and when I look at the socket window I read something about memory block is free and about memlist or something, next time I’ll write it down but anyone knows why it happens and how to stop making it happen?

I would like to add that I seem to be unable to do undos at object mode. And it also writes a message in the console, something like “memoryblock free: pointer not in memlist”