Wait for it... *BANG*
When you fix missing textures, all you are doing is replacing any missing textures with a default texture, which perhaps is AFALL1 for you. If there are missing textures that you replaced, also try using the replace feature. Just replace any or all of a texture, in this case AFALL1, with a texture you may consider the default texture for your map. That way you'll have a much lesser chance (or perhaps no chance) of unintentionally encountering an AFALL1 texture. Or, for an even more efficient method, just change your default textures.