Cannot submit press RETURN

[Knight dude]

I was chatting in some server. I was typing and gonna press RETURN key but it won't work. How do I fix it I try every way I could think but all of it won't work.

[Ad Bot]

[Darkness ZXW]

press right shift

[Greek2me]

Press all of these keys once:
 - L shift
 - L ctrl
 - L alt
 - R shift
 - R ctrl
 - R alt

Sometimes Blockland thinks that they are still held down, which causes things to work strangely. Pressing them again resets it.