How I Met Your Mother - Episode 3.15 - The Simmons Report

While at the bar, Marshall tells the gang about something terrible that happened at work: one of his law school buddies got yelled at for writing a crappy report and is told to get in the game or get out, that put said buddy in weird state; later, Marshall has to hand in a report and fears that he'll get yelled at by the boss too. The gang tells Marshall that he should stand up for himself. Marshall marches in the boss' office and quits. Stella appears in the episode.

Source: SpoilerFix