Hi there! I'm not familiar with the errors like that, but i would like to help or atleast give some ideas for you to try. Are you trying to invite players with Special Characters in their names? Try using other browsers and see if it will work.. :\

Just as QV mentioned. The problem could be those special character names. You can try making a team manually and putting a notification to invite people to join your team OR you can ask them to make the team and transfer leadership.

Could also depend on your name. There's a guy in my group with a not so friendly name and he always has to have people invite him to teams and then make him leader because the game won't let him form teams.