Door travel interrupted / force limits tripped

A LiftMaster or Chamberlain 4 up-arrow flash with 1 to 4 down-arrows means the door's travel was interrupted or the opener hit its force limit — something stopped the door mid-run or made it work harder than its safety setting allows. Common causes are a binding door, an obstruction or ice at the floor, tracks knocked out of line, or a door that's gone heavy because a spring is failing. It shows up as a door that stalls or reverses partway.

Check the tracks and the floor for anything in the way first, then do the manual lift test: pull the release cord with the door closed and lift by hand — a healthy door glides up and floats about half open. If the door lifts smoothly but the code stays, the travel and force settings just need reprogramming, a DIY job with the manual. If the door is heavy or crooked, stop: that's spring and cable territory under dangerous tension, and cranking the force limit up to overpower it only hides the real problem — call a tech.