Q: open with: stuck on Fetching...  in Get Info

Hello nealt2,

Thank you for using the Apple Support Communities. I know having an issue with Finder on your Mac is not what you expect. If I understand correctly, you are unable to use the “Open With” option when you use the Get Info command on a file. To narrow down and resolve this issue, I suggest these steps:

1. First, run a quick scan on your disk and test this issue again, in case this is a simple drive or OS issue that can be easily fixed.

Disk Utility (El Capitan): Repair a disk

2. Next, use Safe Mode to start up your Mac so that it performs certain checks, delete system cache files, verifies your startup disk, and attempts to repair directory issues if needed.

Try safe mode if your Mac doesn't finish starting up
Limited graphics performance in OS X recovery or safe mode

3. You can figure out if unexpected behavior is related to user file or setting by trying to reproduce the issue from another user account. This process includes creating a new user account, logging in to it, and testing for the issue.

How to test an issue in another user account on your Mac

Cheers!