Mike,
{caption} or {headline} are not appropriate for naming files or folders. They can easily be longer than the maximum length for a file/folder name.
Also, you should be using the non-IPTC date variables. {year4}, (month0}, {day0}, etc.
-Kirk
Kirk, those variables came from a video on how to use Photo Mechanic Variable. Sure, I will change them as you suggest, but before I do so, what's the difference?
Earlier this evening, Andrew from Camera Bits Tech Support connected to my computer, and both solved and repaired the problem. Rather than mangle the explanation, perhaps you can ask him what we did, and why, and explain it properly.
What would you suggest instead of the variables I'm now using for renaming? I did this the way the video indicated, and I typically don't put in long strings of text. I keep everything as short as is reasonable.