Apk file isn't building?,Apk file isn't buliding

While Buildind apk file unity shows "**Building player Failed** And shows following errors: **UnityEditor.BuildPlayerWindow+BuildMethodException: 3 errors at UnityEditor.BuildPlayerWindow+DefaultBuildMethods.BuildPlayer (BuildPlayerOptions options) [0x00207] in C:\buildslave\unity\build\Editor\Mono\BuildPlayerWindowBuildMethods.cs:172 at UnityEditor.BuildPlayerWindow.CallBuildMethods (Boolean askForBuildLocation, BuildOptions defaultBuildOptions) [0x00050] in C:\buildslave\unity\build\Editor\Mono\BuildPlayerWindowBuildMethods.cs:83 UnityEngine.GUIUtility:ProcessEvent(Int32, IntPtr) ** **Build completed with a result of 'Failed' UnityEngine.GUIUtility:ProcessEvent(Int32, IntPtr)** **Assets/Standard Assets/Utility/SimpleActivatorMenu.cs(10,16): warning CS0618: `UnityEngine.GUIText' is obsolete: `This component is part of the legacy UI system and will be removed in a future release.' ** **Assets/Standard Assets/Utility/ForcedReset.cs(6,27): warning CS0618: `UnityEngine.GUITexture' is obsolete: `This component is part of the legacy UI system and will be removed in a future release.' ** Please sir tell me how to solve this problem I will be thankfull to you. ,while building apk file unity says "Building player Failed" And shows following errors: **UnityEditor.BuildPlayerWindow+BuildMethodException: 3 errors at UnityEditor.BuildPlayerWindow+DefaultBuildMethods.BuildPlayer (BuildPlayerOptions options) [0x00207] in C:\buildslave\unity\build\Editor\Mono\BuildPlayerWindowBuildMethods.cs:172 at UnityEditor.BuildPlayerWindow.CallBuildMethods (Boolean askForBuildLocation, BuildOptions defaultBuildOptions) [0x00050] in C:\buildslave\unity\build\Editor\Mono\BuildPlayerWindowBuildMethods.cs:83 UnityEngine.GUIUtility:ProcessEvent(Int32, IntPtr). And Build completed with a result of 'Failed' UnityEngine.GUIUtility:ProcessEvent(Int32, IntPtr) Assets/Standard Assets/Utility/SimpleActivatorMenu.cs(10,16): warning CS0618: `UnityEngine.GUIText' is obsolete: `This component is part of the legacy UI system and will be removed in a future release.' Assets/Standard Assets/Utility/ForcedReset.cs(6,27): warning CS0618: `UnityEngine.GUITexture' is obsolete: `This component is part of the legacy UI system and will be removed in a future release.'** Please tell me how can I solve this problem.I will be thankfull to you.