I have an Canon AE-1 and the film advance lever will not advance the film, the lever goes half way. The shutter will not release. Thanks
The film is either at the end or stuck. The shutter will not release unless the film advance lever has gone all the way and back.
Make a note of the frame counter. Rewind the film and remove it from the camera (When you feel the film to come loose from the receiving spool, stop rewinding to prevent the end of the film to disappear inside the can. This way you can reload it if it was stuck in the middle.) If the film was completely exposed, take it to be developed.
With the empty camera, try to advance the lever and release the shutter. If this works, the problem was the film and not the camera. Everything is fine. If the problem persists, take it to be repaired.
If the film was stuck in the middle, load it again into the camera. With the lense cap on (preferably in a dark room or similar) 'shoot' as many 'empty' frames as you had on the counter plus two more. Finish the film and develop the pictures.
If the film stucks again at the same place, rewind it and develop normally. It was a bad film.
Hope this helped you to solve the problem.