open daz, open the logfile( Help>troubleshooting>View Log File).
Delete everything, save file.
if you remember when it started, and what you have installed since then, start with a single item.
load Item, if no error message, open logfile and clear/save
Delete item from scene, go to next item until error is given.
check log file
There must be a:
Duplicate file ( or something like that) followed by a path ( c/gen8/data/etc)
Go to file in explorer and remove file