Use old manual lenses with non chipped adaptors on a regular basis in Manual mode both stills and Live View. Just tried my 1.4x TCs. The Canon refuses to play nice and throws Error 1. My Kenko continues to play well with others. It would seem that we have a winner!
Picked up the Kenko some time ago as the different physical design allows it to be used on ALL of my lenses. You should get one, or two if you sell your Canon TC to cover the cost of buying the others.