This is a old post but should still work:
https://www.ubbcentral.com/forums/ubbthreads.php/ubb/showflat/Number/181903Scratch that I looked and it appears that it was moved.
Searching for new location
Okay found the same line that was moved to:
libs\html.inc.php
around line
01665: if (!$icon) { $icon = "book.gif"; }
Try changing book.gif to blank.gif
Remember it is case sensitive.
