Using Brewery 3.0.0
Recipes set to use either Crimson or Warped barrel variants for aging fail to load.

I think wood types 7 and 8 (nether wood types) aren't supported yet. You can only have woods 1 through 6 which are all the overworld wood types.

What version of Minecraft are you using? 7 and 8 should be supported in 3.0

This is on Minecraft 1.16.4

I too am having this issue on my server.

I haven't tested this first hand, but one player said they were able to age brews in nether wood barrels.

It looks like it's enabled to age, but not enabled to be specifically called out as the wood to age in.

I hope this narrows it down.

@Sn0wStorm Here's all I'm doing to get the error. Changing wood-type to 7 instead of 2 for mead.

I've done some looking into the code that was added for the 1.16 wood types. Perhaps this might have a clue for you? This is from the LegacyUtil.java file. I'm unsure if maybe adding the nether wood type to that would fix it but perhaps?

I am also experiencing this issue on version 3.0. When the plugin is reloaded with a barrel type of 7 or 8 specified in a recipe, it's produces the error as described.