The bug
The exception thrown by the method net.minecraft.nbt.NbtAccounter.accountBits(long) (20w07a Mojang name) when too large NBT data is read is missing a space in front of "bytes".
Current message
"Tried to read NBT tag that was too big; tried to allocate: " + this.read + "bytes where max allowed: " + this.max
Fixed message
"Tried to read NBT tag that was too big; tried to allocate: " + this.read + " bytes where max allowed: " + this.max