Problem with WebGl Build.

I made a game in C# and am trying to upload to the web from WebGL but the build keeps failing in the middle and I get this error(located below). When I click on the error it sends me to the SimpleActivatorMenu.cs script from the Standard Assets Utility Asset. This is after I updated my version of Unity. What do I do? UnityEditor.BuildPlayerWindow+BuildMethodException: 2 errors at UnityEditor.BuildPlayerWindow+DefaultBuildMethods.BuildPlayer (UnityEditor.BuildPlayerOptions options) [0x00275] in <9ba1187881a84a08b5f9c4cb333d7a6a>:0 at UnityEditor.BuildPlayerWindow.CallBuildMethods (System.Boolean askForBuildLocation, UnityEditor.BuildOptions defaultBuildOptions) [0x00080] in <9ba1187881a84a08b5f9c4cb333d7a6a>:0 UnityEngine.GUIUtility:ProcessEvent(Int32, IntPtr)