Cannot open game

When I click play, I get the following:

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null is not an object (evaluating '/(\d+\.\d+)/.exec(this.osVersion)')

getOSNameAndMajorVersion@http://www.callofwar.com/ww2-dev/js/main-built-min.js?bust=1474441998:30906:36

UltActivateGameAction@http://www.callofwar.com/ww2-dev/js/main-built-min.js?bust=1474441998:31013:54

onConnected@http://www.callofwar.com/ww2-dev/js/main-built-min.js?bust=1474441998:47899:62

[native code]

notify@http://www.callofwar.com/ww2-dev/js/main-built-min.js?bust=1474441998:272:15

publish@http://www.callofwar.com/ww2-dev/js/main-built-min.js?bust=1474441998:346:39

onOpen@http://www.callofwar.com/ww2-dev/js/main-built-min.js?bust=1474441998:3204:21

connect@http://www.callofwar.com/ww2-dev/js/main-built-min.js?bust=1474441998:3341:16

init@http://www.callofwar.com/ww2-dev/js/main-built-min.js?bust=1474441998:3301:17

start@http://www.callofwar.com/ww2-dev/js/main-built-min.js?bust=1474441998:47894:27

start@http://www.callofwar.com/ww2-dev/js/main-built-min.js?bust=1474441998:847:24

startAll@http://www.callofwar.com/ww2-dev/js/main-built-min.js?bust=1474441998:898:30

[native code]

j@http://www.callofwar.com/ww2-dev/js/external/jquery/jquery-3.1.0.min.js?bust=1474441998:2:29573

http://www.callofwar.com/ww2-dev/js/external/jquery/jquery-3.1.0.min.js?bust=1474441998:2:29883

Details:

TypeError: null is not an object (evaluating '/(\d+\.\d+)/.exec(this.osVersion)')