Build error [0x00242]

I got this error: UnityEditor.BuildPlayerWindow+BuildMethodException: 20 errors at UnityEditor.BuildPlayerWindow+DefaultBuildMethods.BuildPlayer (UnityEditor.BuildPlayerOptions options) [0x00242] in C:\buildslave\unity\build\Editor\Mono\BuildPlayerWindowBuildMethods.cs:190 at UnityEditor.BuildPlayerWindow.CallBuildMethods (System.Boolean askForBuildLocation, UnityEditor.BuildOptions defaultBuildOptions) [0x0007f] in C:\buildslave\unity\build\Editor\Mono\BuildPlayerWindowBuildMethods.cs:95 UnityEditor.BuildPlayerWindow:BuildPlayerAndRun() please help me ☺ ☻