I’m experiencing a similar issue, but haven’t found a solution yet.
I suspect it has to do with referring to a conditions file within a nested loop. Perhaps it’s related to this issue and this related forum post, but I’m not sure.
In my case, the debugger shows that the string that refers to the image file is split into an array of separate characters. You can see it below: PPImgfile should start with “PPImages/”, but the string is being split in separate characters instead. Therefore, the script only picks up the first char of the image file name (in my case ‘P’, in your case ‘b’?). Explicitly translating the image file name to a string at the beginning of a routine didn’t help.
What does your browser’s debugger say in your case?
