Do you have photo names with slashes / in them? If so, then that would definitely freak things out. I think that's what %2F expands to.
Or, do you have an album called "good_companion" and in it a photo "072_paris"? Something is then going wrong and not understanding the /.
Pick a photo that keeps generating that error when you look at it, and go into edit and look what's set for "Filename" and "Internet Address" to see if anything looks odd.
Seems strange that everything works but you still get errors. You
could try changing the G3 error logging level to "debug", although I don't think
G3 really does much in the way of useful logging. Plus, changing the logging level seems to be done in more than one place. Or ... just ignore the
errors 😁
--
Adrian