The render files are still in AppData-Roaming- Poser Pro- 11-Render cache but not in a format you can use in most graphics apps. Its been a month or two since I updated to get rid of this bug and can't remember if they all reappeared or if it repopulated. Might be worth a try to back up these and your other settings, update and replace if they've gone. I'm on 11.2.307 for Windows but there is a newer version.

Check here- no version numbers only dates

https://www.posersoftware.com/downloads

Poser 11 , 180Gb in 8 Runtimes, PaintShop Pro 9
Windows 7 64 bit, Avast AV, Comodo Firewall
Intel Q9550 Quad Core cpu,  16Gb RAM, 250Gb + 250Gb +160Gb HD, GeForce GTX 1060