Is there a limit for the Auto Troop Hider? It says I have reached mine but I have none & can't  purchase any!!

Commander...I have 5 - 4 hr troop hiders in my BlackMarket. I did not buy them so I presume I either won them or was awarded them as part of a bonus pack..As a test I tried to purchase another 4 hr, game would not let me purchase..So Look to see if you have an 8 hr or a 4 hr troop hider..if you do the game will not let you purchase any until you have 0...but game will let you win or be awarded them