Thread:CardBoss14/@comment-24019770-20140210023014/@comment-11454852-20140210024246

Directly from the YGO Wiki

''On September 10th, 2011, episodes 135-136 were merged into a one hour episode, which aired on Toonzai. However, the ending was edited so that after Aporia lost, the Divine Temple disappeared from existence. As a result, the special one hour episode ended with the celebration of Team 5D's victory as the series finale. The last season was not dubbed, leaving the series incomplete just like how the previous series was also left incomplete. According to the Toonzaki webmaster, they ended the series like this due to "low ratings". ''