Sometimes, when swapping characters, the game loads into screensaver mode and is stuck there, making doing activities in the game unworkable. Pressing the escape key doesn't help. Then if I switch off the game and try to restart it, it says "The game is still running". At this point, I have to restart the computer to be able to launch the game again. I have disabled screensaver mode in the settings, so not sure why this happens. Apparently the game is set to always load into screensaver mode, even when you try to disable that in settings. It just doesn't always let you leave screensaver mode.

Here's a picture of what the bug looks like.

Then I get this message when I try to start the game again without restarting the computer

Fortunetely I discovered that clicking the refresh button sorts things out. Still bothersome to deal with though.