Every time I run a simulation in 360 and need to stop it prematurely, when I hit the stop button it says it's stopping but just hangs up. Even if I close the application and reopen, it thinks the simulation is still running. Eventually, sometimes it shows it stopped and allows me to start working with the file again. Any input would be greatly appreciated. Thanks!
Stopping 360 can take a bit of time and patience. If you really want to kill the job and you don't care about the results then just stop the job from the Simulation Job Manager.
If you want the results then you will have to wait for the analysis to finish after hitting stop. Closing and reopening CFD won't help.
Have you upgraded to SP1 of 360?