Found the issue! It's a conflict with Weapon Stat Adjuster! Something that WSA does with summoner related stats is conflicting with FaeLib which cause it to conflict with just about every other mod, regardless of whether or not it adds summoner related items (I.E Magic Storage)

I unfortunately can't seem to be able to recreate the issue with any of the mentioned mods

i've been getting this same issue

Hey, it looks like your mod might be conflicting with Calamity and Arsenal, potentially other mods as well! While this mod is installed, big content mods have problems loading past the Configuring Content stage. Just thought you should be aware of this!