Uh.
You'll need to provide more information.
Like what kind of online game were you trying to join? What color game completion check mark do you have if you're wanting to join a game someone else has created?
When I create a ranked round game, players that have a yellow or red completion check mark don't get to play in the game I created. Only players having a green completion check mark get to joining me for a game.
You might also want to figure out how to make a capital letter when one is appropriate.