Answer:
Ok this is the summary I heard about which my dad told me since he works for Disney Channel.
Summary Plot: The So Random Cast did a sketch (idk which sketch it is) which Marshall didn't like and said it sucked. The so random cast talks to Marshall about the sketch and Marshall just said to try one again solemnly. The cast didn't think of one to do so they pleaded Sonny to talk to Marshall privately to do the sketch that stunk. While walking up there Sonny was about to talk to Marshall and saw him crying, Sonny went up to him and asked why. Marshall just didn't seem so Marshall anymore, Sonny came and didn't know how to cheer him up. She thought of an idea to cheer him up like following his dream to be in a One Man Show. Marshall was excited about this and went out there and gave it his best shot. Until a man came inside and asked Marshall for an opportunity to be in a One Man Show on a studio. Marshall said yes and agreed. The cast has a new director that is mean and rude to them. The cast plans to get Marshall back but fails. At the end Marshall comes back to be the head director.
That's what I HEARD but not sure by and enjoy. P.S this episode airs somewhere in December 2010!