When you try to place the blocks above, or below the height limits, the warning message still includes the word "blocks", which Java doesn't include anymore since 1.17. It is also inaccurate since the height build limit for the message is 255 (or 319 if you count experimental caves & cliffs/upcoming 1.18 update).
Update 4.21.2026
Maximum build height message is still inaccurate and exists as a parity with Java.
The game shows:
“Height limit for building is 320 blocks”
However, blocks cannot be placed at Y=320 (only up to Y=319).
This issue occurs in all dimensions (Overworld, Nether, The End, and custom dimensions).
On Java Edition, the maximum height message correctly matches the actual limit (e.g., 319 in the Overworld).
Step to Reproduce
Try place a block at the height limit.
Expected Results
The message says: Height limit for building is "block height number", maximum build height is 319.
Observed Results
The message says: Height limit for building is "block height number" blocks, maximum build height is written as 320, but you can build up only to 319.
Can reproduce in beta 1.17.30.23 on Windows 10