Affects Version/s: Minecraft 17w50a
Fix Version/s: None
If a command block attempts to run a particle command that would not be seen by a player (e.g. there is nobody online and the particle is in spawn chunks) this message is printed in the server console regardless of gamerules:
This can lag server control panels which attempt to parse the log output and overall leads to an unreadable server console.
start a server instance
generate a flatland world with the spawnpoint at (0,0)
place a repeating command block
insert this command:
Look at the server console.
Note: This does not appear to be true for functions.