There seem to be several issues that cause `RUN` to _hang_. By "hang" I mean that the prompt hasn't returned and its obviosu the program isn't executing. This is usually in conjunction with an error report. The error shows up and the prompt never comes back. You can ^C to get a prompt but then the environment seems prone to _hanging_ instead of executing. I think there is a bug report for `RUN "not_found.bas"` hanging when the "not_found.bas" is either a missing file or one with an I/O error. A parse error might cause it too? I've seen some other random times where errors are showm but the bwBASIC prompt does not come back. I think this may also be caused by a bug in `FUNCTION ... END FUNCTION` or `SUB ... END SUB` blocks. This is a seldom and randomly occuring bug and I haven't spent the time to determine exactly when it happens. This is just a reminder there is one of those _80% of the time it works 100% of the time_ style bugs lurking in bwBASIC. Let the "bug hunt" begin!!