Question Error with possibly abandoned plugin (CustomAttributes)


New member
Jan 17, 2022
Hi y'all, I recently discovered this plugin called CustomAttributes and I like it cause it lets me prevent players from placing blocks so I thought I'd give it a go. If you know an alternative plugin that prevents placing items if they have data attached, feel free to let me know but after some searching this is the only super small one that did what I needed :)
Unfortunately it seems that if you open an anvil and click anywhere, it throws an error (see error below). I don't even need that feature necessarily but it might be easier to fix it than remove the whole feature.

Plugin resource link:
Source code where I think it might be going wrong (EPL-2.0 license):
The error in question:

I don't know any coding, I'm just a simple server admin who tries to make a cool server and thus I can't really fix this problem on my own, so if one of you lovely people could, I'd be really grateful <3