Same problem. I had one that I used for all my photos and editing, and never had a problem. I now purchased a second passport ultra to use as backup and I’ll be darned if now I can’t make either one stay connected to my IMac. They initially come up on my desktop as being accessible but then after about 45 seconds they disappear and anything I’m tryng to do reverts to a ‘please install Passport Ultra Drive’ message. So frustrating! I can’t wait to get information. I haven’t updated my operating system or anything different.
