Warped spin-on oil filter adapter? y-block

[Sid]

You may also try taking a pick or something with a sharp point and running it in the area where the gasket went for the original canister. Just in case there is a small piece of the old gasket that was missed. Also I think the adapter has a top. Also before torquing down maybe try turning back and forth a few times to help the adapter seat. Worth a try...