Problem creating new library with photos and videos from NAS folder

Hello,
I have a desktop running Plex server. I have a QNAP NAS on the network where all my media is stored. Desktop Plex server let me create libraries using various folders from the NAS but it will not let me create a photos library with my NAS folder that contains home videos and photos. It just errors out and says it was unable to add that folder to the library. Any ideas? Could it be a folder size issue? Thanks