You should always tell your boss important things.
Scott found a bug in the code for a project at work shortly before a deadline.
Scott doesn't want to stress out his boss.
Scott explains to his boss immediately what the bug is and requests help to make sure it is fixed in time.
Scott hides the fact that there is a bug from his boss and tries to fix it before anyone finds out.
The boss is able to help Scott get the necessary help to get the bug fixed by the deadline.
The bug doesn't get fixed on time and the boss and client get very upset.