I have a very fast computer with lots of RAM and no problems with any of my other programs. This "not responding" error happens to me all the time. It's really annoying. I try to do something then wait - maybe have a cup of tea (lol) - then come back and it's finished the task and I can continue.

This is definitely a bug in the program that has not been resolved in since the same issue was there in the last 2 versions as well. They need to work on the programing to improve stability of the program.