How to fix “Aborted! Process finished with exit code 1”

I was working on a website in Flask/Pycharm for a little while, ran into a few problems and didn't get back to it for a few months. Last time I used it there were no issues with running the app but now whenever I try to run it all I get is "Aborted! Process finished with exit code 1" and no other information or clues as to what the problem is.

I've tried updating Pycharm and I've also tried changing the port it runs from but neither changed anything and I still get the error. Also created a blank Flask project to see if there was an issue with my internet settings but that worked straight away without any issues.