If you are experiencing a "looping bug" and don't want to download the new 0.5.6 again, you can avoid it by skipping class on Monday (Unless the task you are trying to do says so) and also avoid making more money than $400, that should fix it.
(If you are in a loop already and can't advance with the task, you need to start a fresh save file, remember that you can skip the whole first week so you don't need to go through all of that again)