IMO; it is the Format of a Line. If this does not match, poi_visbilities.txt will not be taken over by Nextgen
see my File - open with texteditor (Windows Editor)
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
!!"**
if a branding.zip with a modified Icon is used then a poi_visibilities.txt is often included here /ui_nextgen/Defaults/poi_visibilities.txt. I always delete these before using the branding.zip