Garage door only opens a foot from ground

Question

My garage door only opens about a foot from the ground and stops. Press the botton againa nd it goes down, but again will only open a foot. Does the same thing with both remotes and main controller. This never happened before until I wanted to open the garage door just enough to get air inside so I pressed the botton and waited until the door was slightly opened and then I pressed the button and it stopped. Now that is as far as it will open.

Any ideas?