Alright I think I know what the problem is from that.
Line 5556 is checking to see if the slot it's about to draw is a locked slot or not. It does this via an array, which resides in $gameParty, and is put there when the plugin loads its parameters. The error given below is that it can't read property 0 of that value. Which means it isn't initialized. But since it's always initialized on load, there are only two ways this could happen:
- The plugin silently failed to load
- If this were true though, you'd not get to the point where it would cause this crash in the first place, as the menu would not be modified to allow access to it, the functions wouldn't be defined, etc.
- You are attempting to load into the crafting system from a gamesave that was saved before this plugin was imported into your project.
I suspect the problem is #2 - you're using an old save to test. Many plugins have this problem, where they rely on loading data in a specific way, so that it can be saved in the save file later, and as a result, the plugin will not work until you start a new game to test it.
Give that a shot, I'm sure it'll straighten it up for you.