If unexpected items somehow appear in loom top slots (banner slot and dye slot) and you try to choose recipe - minecraft crashes with `ClassCastException` because of item in banner slot being not `Dyeable`.
I haven't tested bottom loom input slot so I don't know if there is same problem with it.
I think the solution is to not show available recipes if input items are `wrong` (somehow, maybe with tags or idk).
I'm not sure if I should report this as I don't know if it can be done in vanilla because generally you can not put wrong items in loom slots (maybe you can with datapacks but I don't know how to create datapacks).
Also I don't know how to reproduce this because I found this in earlier version with plugin.
And I didn't find any issue related to this problem so I guess it's present in last version as well.
Thank you for your report!
However, this issue is Invalid.
Your game, launcher or server is modified.
If you can reproduce the issue in a vanilla environment, please recreate the issue.
Any non-standard client/server/launcher build needs to be taken up with the appropriate team, not Mojang.
A world which had previously been opened with a modified client might be corrupted. Please try reproducing the issue in a newly generated world.
Any plugin issues need to be addressed to the creator of the plugin or resource pack.
If you have problems on large servers like Hypixel, please contact them first as they run modified server software.
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