Dolphin fails to load some files from SD card

[R̢i҉̴̛͜d̷̕҉̴l̨̧͠͡e͘͜͠y̴̶͡͠͞]

This started happening a while ago. First, it was with one of the stages, now it happens with some characters. For example, Pit. Some of the recolors fail to load (so, either game freezes or it loads files from the ISO) even though they have same or even smaller file size as those that load. Is there a way to fix that?