Cannot close GUI if an error is encountered during play

I still have the code in which an error occurs if the Import button is hit and there are no scripts configured yet (Issue ~~#13~~)

In such a case,the error is seen in the terminal and the GUI hangs. The close button wont close the GUI and you are left with an orphan UI that will die only on shutdown of system!

Although Issue ~~#13~~ is resolved, in future, if such errors occur, then the GUI should quit in a dignified manner.