Getting WD My Passport Ultra to work with OS El Capitan

I have a My Passport Ultra preformatted for earlier Mac OS. How do I get it to work with El Capitan?

Hi,

If the drive was already pre-formatted for Mac, it should be plug and play on the new OS.

Thank you. It wasn’t but I figured out how to reformat it.

This might be related to the same issue here: My Passport not mounting on macos 10.12