9:45 AM PT -- Kid Cudi just posted a video update detailing what happened during his jump offstage, "This is what happens when a 40-year-old man tries to prance around off stage like he's 26."

He says it's a major setback but reiterates to his fans that he's OK, and will still be touring in the coming months as long as he gets his doctor's approval. Safe to say he's learned his lesson.

Kid Cudi cut his Coachella set short Sunday ... after breaking a bone by jumping off the stage.

Late into his performance on the Sahara stage, the rapper was getting off the platform ... noticeably swaying back and forth. At one point, Kid Cudi jumped down hard off the stage -- and was struggling to get up.

KC found help as 2 security guards tried to help him walk it off -- but he was unable to finish the performance.

It appears Cudi did some damage -- he told his fans on X he broke his foot.

Cudi said, "Hey guys, so I broke my foot today at the show. 🤦🏾‍♂️ just leavin the hospital. Never broken a bone before so this is all a bit crazy. I wanna thank u all for ur concerns and well wishes!! I love yall man. I heard yall still ragin when I was offstage. Made me smile big."

Though Kid Cudi's set ended early, the crowd wasn't too shortchanged. Cudi only had one and a half songs left in his Sunday set.

The Coachella live stream -- which documented Kid Cudi's injury -- proceeded to play a recording of his hit, "Pursuit of Happiness," to make up for his absence.

KC couldn't say goodbye to his fans  ... some of whom seemed super confused.

This was Kid Cudi's first time back at Coachella since 2019 ... so it's a bummer.

It was a rough weekend for musicians ... Luke Bryan took a hard fall onstage during the Coast City Country Festival in Vancouver. Unlike Cudi, LB was left unscathed from his fall ... he even laughed off the whole thing!!!