Have you looked at the other plugin threads?
uh, no. any of the hundreds in particular you could recommend me to try then?
pardon my ignorance for not looking in threads labeled with subject matter other than what i need help with.
Nevermind...it's working. I'm an idiot.
I opened a random files to test with and they were outside of the ICO parameters.
For anyone interested, the ICOFormat 2.1b1 plug-in is working in Photoshop CC.