tiny bug: files in Tiled Build fail to write to images if file naming pattern parsing fails
stemming from this discussion: https://gaea.community/d/460-exporting-textures-with-udim-naming-instead-of-x-and-y-coordinates/4
wanted to see if mathematical expressions would evaluate inside brackets (i.e. [y*5+x] to write images to a string for UDIM) and found the images don't write / caches remain in accompanying bin folder
only mention it because finding out you made a small typo after several hours of building would be a bummer; probably quick to throw an input validation check before the build swarm fires