This is the Happy Wars Management Team.
From the League Season switching in January 21st 2016, there was the following issue:
Details
Blank League Rewards window got displayed for the players with League Ranking under 5000th while there were no League Rewards for these players.
This issue would not affect the League Rewards for those players with 5000th or higher ranks in the league. Still, the League Leaderboard and actual ranking for Xbox 360 and Xbox One are all independent.
Thank you for your understanding and cooperation.
About the League Rewards displaying