LibClassicAddonsFix fixes classic addons lua errors, which are caused by API changes in different WOW expansions or regions. Typical lua errors like: C_AddOns.xxx attempt to call field 'IsAddOnLoaded' (a nil value), C_Item.xxx attempt to call field 'GetItemInfo' (a nil value)
README on github: https://github.com/doneykoo/LibClassicAddonsFix-wow-addon/blob/main/README.md
Curseforge page: https://www.curseforge.com/wow/addons/libclassicaddonsfix