Can't start a new game in Garry's mod

The game works fine, but when I click “Start New Game” no maps show up and I can’t click anything.

So I checked the console, and here’s the error message;

**

 Error: Argument 'ControllerNewGame' is not a function, got undefined
    at pa (asset://garrysmod/html/js/thirdparty/angular.js:16:79)
    at qa (asset://garrysmod/html/js/thirdparty/angular.js:16:187)
    at asset://garrysmod/html/js/thirdparty/angular.js:50:219
    at asset://garrysmod/html/js/thirdparty/angular.js:42:154
    at m (asset://garrysmod/html/js/thirdparty/angular.js:6:312)
    at k (asset://garrysmod/html/js/thirdparty/angular.js:42:16)
    at e (asset://garrysmod/html/js/thirdparty/angular.js:38:198)
    at asset://garrysmod/html/js/thirdparty/angular.js:37:332
    at k (asset://garrysmod/html/js/thirdparty/angular.js:145:258)
    at asset://garrysmod/html/js/thirdparty/angular.js:87:299
**

What do I do?