In an rpg modpack I’m creating, there is an issue where other RPG series mods don’t recognise if I have runes in my inventory, they just give me the message “Missing ___ Rune” https://ibb.co/mVk8wVRP

This is not an issue of the Runes mod. Also, there is no such issue in general.

This is most likely an some conflict in your installation.

I recommend joining Discord to get help with your specific problem.