Can't join Trial of Zeal

hueyTW

Whenever I click the button of join game, an error window pop out.  I already try to click button many times and restart my app. I can successfully join other event, but only Trial of Zeal pop an error message box.

My last match of coalition event Trial of Ambition end after the event deadline. After the match, the event reward don't pop out. I don't know whether it is the reason I can't join  Trial of Zeal.