My rear derailleur hanger went yesterday on the commute home. Luckily it was as I started off again after a turn. Still managed to take out 2 spokes itself and possibly the derailleur itself. Luckily, I had spares back to my knackered old Shimano for now.
Friendly reminder from a jaded bicycle mechanic - it’s more often than not a bent hanger (or bent jockey wheel cage), not a limit screw issue.
The limits don’t tend to work their way out of ‘set’ (unless you ride really hard or are very unlucky).
Good shifting, regular maintenance and checking your drive train goes a long way to avoiding mishaps like this! Thankfully our lord and saviour Calvin at Park Tools can help teach how to trouble shoot little niggles to avoid them becoming problems like OPs! It also means you’ll get to feel when shifting is a bit suspect (ghost shifts, chain skipping etc.) and you can pick up on them earlier.
Thankfully it’s not rocket surgery!