I was disappointed today when I unpotted my paph. PEOY and discovered that many of its roots were unhealthy, a good number dead. Very surprising, because it seemed to be doing pretty well. I kept the ones I thought were ok, but I don't know how well the plant will do after this repotting Hopefully i can help it bounce back.
I'm sure it will bounce back... patience and as Bill said above it was v probably kept too wet. I'm a believer in watering with something like KLN when I have had the problem and have always found that it really promotes root growth. Good luck and keep us posted.
I've had this happen with some paphs in the past. Sometimes I would catch it in time, other times, I was too late.
This is the primary reason why I've been moving all my slippers over to transparent plastic pots. What a difference that makes! Not only do I now get a very clear and constant visual of the root-level moisture conditions, it lets me know when a plant's roots are going dormant so I know to cut back on water. Plus, if something's going astray, I know pretty quickly and can move to correct the problem early -- nip it in the bud you might say.