Hah! I was right.

It has nothing to do with UAC - ignore everybody else's advice. They were all good things to think about, but have nothing to do with you.

You need to manually create an empty text file in the exact place it was telling you. It does not have to have anything at all in it.  A blank text file.

http://www.renderosity.com/mod/forumpro/showthread.php?message_id=3753907

http://forum.daz3d.com/viewtopic.php?t=77881

http://www.renderosity.com/mod/forumpro/showthread.php?thread_id=2732462

http://www.renderosity.com/mod/forumpro/showthread.php?thread_id=2806232&page=2#message_3673689

http://www.renderosity.com/mod/forumpro/showthread.php?message_id=3673327&ebot_calc_page#message_3673327

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Renderosity forum reply notifications are wonky. If I read a follow-up in a thread, but I don't myself reply, then notifications no longer happen AT ALL on that thread. So if I seem to be ignoring a question, that's why. (Updated September 23, 2019)