Front-end code (or a desktop app) is a bit different because you don't crash out in front-end situation. But I'd still throw and stop the current function/proc

Front-end code (or a desktop app) is a bit different because you don't crash out in front-end situation. But I'd still throw and stop the current function/process and recover at a higher level than let the code continue to run. The user shouldn't be stopped from doing anything else or trying again.