I'm running into this same issue now actually. I think the GM:S version is the issue, as I was able to get a game compiled on GM:S 2 from earlier this year to run, but not one compiled very recently.
the normal kernel exploit runs off of a bin file converted to mp4 right? and the sm4sh movies are in mp4 format. i have no modding/hacking experience so i couldn't do this myself but could this be a possible way to install a true homebrew channel?
okay the .bat file won't unpack my romfs, the error log says
"A subdirectory or file tempdata already exists.
error: could not open input file!"
i tried re-dumping the game and nothing works, any suggestions?
i used Sunshell to dump some Extdata things (like warriors way saves) and i found these while i was looking for Meet.dat (streetpass mii plaza save) are they the same thing or something completely different??