Internet Explorer is becoming non-responsive

I have a very similar issue. We are running our tests in IE11 using TC 11.20 on virtual machines. After about 1 hour into the test run there are a particular set of controls that stop responding.

I fixed the issue by writing a small script that logs out of our application, kills all IE processes, then restarts browser and logs in. This script runs about every ten tests in our test run (approximately every 30 minutes). 

I suspect this is a memory leak issue in IE and or Test Execute but would require some more in depth troubleshooting. I did try running IE developer tools 'Memory' feature to watch memory usage while tests were running in real time and it does climb contunously during my test run and fairly high. I would assume to the point where my application eventually becomes non responsive. 

I also came accross someone reporting a similar issue with Selenium tests (after a Google search for issue) and they resolved by restarting the browser perididocially so I suspect this may not be an issue exclusive to Test Complete. 

I have a ticket open with SmartBear but no response yet, perhaps you can also open a ticket if you havent done so already?

You might also want to check that your VM's exceed the minimum system requirements for Test Complete. This gave a slight performance improvement on my test hosts but didnt resolve the issue we are discussing. 

I am not sure if you're doing this but if not, it should help.

One of the best practices for testing web applications in a  browser is that after every test case, the browser should be restarted (to ensure proper initliazation of the browser state and prevent interference between test cases). I do that for all my test suites and the browsers perform as expected.

This is definitely a thing that I've been fighting for a while now. There's some kind of memory leak in IE that doesn't occur when running the same test in Firefox. Luckily, we've been able to just run in FF instead of IE. I have run into a situation where FF memory skyrockets (over 2gb virtual memory consumed by the process), but that seems to be tied to a specific sequence in our app.