Plex quits unexpectedly after re-install!

I've been using Plex on my iMac and Apple TV4 since it was launched and have been very happy with it.
Unfortunately, I started having a problem with my iMac freezing and started to diagnose the problem. As I had recently updated Plex, I uninstalled it by dragging it from my Applications folder to the trash, to rule it out as the cause of the problem. I also deleted it from my Log in item list. I also followed the instructions for uninstalling, but the '~/Library' can't be found. I then ended up installing a Time machine back-up to sort out the freezing problem, which looks to have been successful. After some time had passed, I downloaded the latest Plex Media Server to set it up again, but everytime I launch the application, it quits unexpectedly, almost immediately. I have attached the report. I'm not sure if it's because I haven't uninstalled it properly. I really need help sorting this out, as I really miss using it now. I would be very grateful for any advice. Thank you!