ChemDraw: Programs change file opening preference in Mac

On the Mac, installing a new program (For example “Avogadro’ ) can change which one opens files. Apple seems to think apps "own" particular extensions, though Avogadro is very clear in its Info.plist that it doesn't "own" any of these file extensions. 

1. Go to the Finder and do "Get Info" on a file.

2. Where it says "Open With" - you can pick an app or "Other" if ChemDraw isn't listed there.

3. After picking out ChemDraw, you can then click "Use this application to open all.." and click "Change all.." That should solve the problem.