What was your first RV noob disaster (or near disaster)?

Slide refused to retract & it d took some doing to figure out the mechanics of the thing. A few turns on the manual shaft, when found, & off the slide went on its own power. Later in same trip the BR acted up. Took a bit to discover that the storage area floor under the bed had to be removed to gain access to bedroom slide workings.

Gotcha now.