This bug was reported earlier today by a Player. -If a Tower, Mine, or Wall that was Selected got Destroyed the Upgrade/Target Priority Buttons wouldn't disappear. The code used the selected object's ID (an arbitrary number assigned by the game) but since it didn't exist anymore due to it having been destroyed the Game got mad and rage-quit. Now the buttons know they are suppose to go away when the tower does so the Game will remain happy and won't rage-quit on you anymore. If you find a bug that causes the game to crash then a grey box will pop up, gives an error and bits of code. If you can get the information to me through a screenshot or copy/pasting I will try to fix it immediately. -There is a known issue when alt-tabbing. you will get an error box like the game is crashing but there will be an option to ignore- do just that, it doesn't cause any problems. This minor bug has to do with the buildable area showing when alt-tabbing/minimizing, the code is kept in temporary memory which is wiped when alt-tabbing/minimizing but as soon as you ignore it the game continues like nothing happened. This will be fixed soon.