Question: MacBook Pro cannot 'see' external hard drive after it converted to APFS
I have a problem with APFS. I erased my external hard drive and it automatically converted to APFS from MacOS Extended(Journaled). I tried, unsuccessfully, to revert to MacOS.....and unplugged the hard drive. My MacBook cannot now 'see' the external drive despite taking all steps recommended.
MacBook Pro with Retina display, OS X El Capitan (10.11.1)