That is weird...
A few thoughts.
Are these your files or are they one of the ready made files made from other people like scott and botwhat?
If they where ready made I can't think of what's wrong.
It kind of looks like you may have left an open bracket or forgotten a semicolon or something, in these files, if you have made them yourself it is likely that's the problem.
Also f you have made them it MIGHT be the encoding the json file has been saved as, from what I saw mine are encoded in utf-8 and they work fine.
It may have to do with the language of your system, I THINK the bot has had such problems in the past with system languages. Again regarding language, you have written one of these in another language and though the symbols look the same they reference different ones. I don't think this is it cause the bot finds the folders with no problem.
Lastly have you tried with different, maybe longer filenames?
_________________________________________________edit
Oh, also try with different heroes, the heroes actually have an entry in the card list and maybe just maybe nelly makes the bot bug out, not recognizing the hero it has been assigned.