I've had that message pop up only for one specific folder of Darkworld's poses.  The runtime containing those poses is on my D drive where it's always been and I had never had any issues accessing it with PP2010, PP2012, PP2014, P11, P12, P13.   Even though I got the message I could still access the folder and the poses inside.  It used to happen with P11 and P12 and even when I used Mozilla browser to open the library and then it suddenly stopped popping up.  Who knows why?