Sanity Potion Not Usable

[AGP]

I've been having this problem for a while and decided finally that it was time to consult the forum.

For some reason, when I playtest my mod, the sanity potion is unusable. You can select from the inventory but instead of "consuming it", it becomes an object, much like a key or crowbar, to use on another object.

I've no idea why this started happening or even how to fix this.

Any and all help is greatly appreciated.