Not sure what happened was working fine before tried to redownload several times but to no avail. this issue also occurs with ftb:quests

Issue was solved it was due to https://www.curseforge.com/minecraft/mc-mods/cataclysmic-illagers for some reason they encrypt any photo/music that gets put in a modpack alongside it. a fix was to use a downgraded version of cataclysmic-illagers