Describe the bug
Whenever I try to add any item to the item the text shows red and does not allow it. (I am using the Configured mod)
Edit: I also can't change it via editing the server config file directly, as it causes the world to get stuck loading
Versions
sophisticatedbackpacks-1.19.2-3.18.53.868

What value are you putting in the config exactly? Sounds like it is invalid and that's why it is not allowed.

closing given no feedback to the question