Mac wont recognize 1TB Passport but it used to

I have a 1 TB passport I formatted for Mac and PC.  It has worked flawlessly for a year or two exclusivley on the macbook air.  I hooked it up a couple of days back and my mac wont recognize it anymore, I tried on my wifes PC and it comes up no problem.  I have tried turning on and off the mac but nothing seems to help.  Since I can’t access it I have no idea how to fix.  Any help is greatly apprecited.



Did you try multiple macs?

Try to see if the drive appears on disk utility