Everytime I try /u I get the same error "An internal error occured while attempting to perform this command"
I'm on the 5.171.0 Snapshot

Not sure if anyone is still looking at this issue but I just encountered it on my server. The cause is that in newer versions of Spigot and Minecraft they removed noteblocks as tile entities and instead of keeping the deprecated code for backwards compatibility they removed it. I am going to make a quick fix for it and push it to the branch but this means that if you undo noteblocks they won't keep their tones. If you would like a compiled version of this message me on Discord at .