Google play store is not recognizing my devise.Is there a way around this?I thought I was because KNOX was tripped so I delected KNOX thinking this would solve the problem. ..it didnt.There's ways around it its just a inconvenience.
Being rooted and irrevocably tripping the Knox Security flag has no bearing whatsoever on your Play Store issue.
In the first instance I would suggest going into Settings > Apps > Play Store... and deleting the cache and data for Play Store. Reboot phone and see if that helps. Failing that, you will need to wipe the phone's cache in Recovery Mode... see #1.3 of S5 Update Problems - Dummies Guide