WORLDEDIT-3866 - Reported by Random

Hi! First of all thanks for your great work with WorldEdit :) Here is the problem:
What happens?
When using
//replace dirt air
or anything like this I get
[15:15:15] [Client thread/INFO]: [CHAT] Unknown command [15:15:15] [Client thread/INFO]: [CHAT] ...e dirt air<--[HERE]
Whereas //replace dirt works as expected
Expected behaviour
The command should replace selected blocks as with previous versions.
Versions data
Minecraft 1.13.2
Forge 25.0.79
WorldEdit 7.0.0-SNAPSHOT; 4088-4f0506e

Thanks for response!