Getting Errors and can't switch platform to build project on.

I’m trying to build my project for iOS and I’m getting this error:

MissingMethodException: Method not found: ‘UnityEditor.PlayerSettingsEditor.BuildEnumPopup’.
UnityEditor.BuildPlayerWindow.ShowBuildTargetSettings () (at /Users/builduser/buildslave/unity/build/Editor/Mono/BuildPlayerWindow.cs:1189)
UnityEditor.BuildPlayerWindow.OnGUI () (at /Users/builduser/buildslave/unity/build/Editor/Mono/BuildPlayerWindow.cs:913)
System.Reflection.MonoMethod.Invoke (System.Object obj, BindingFlags invokeAttr, System.Reflection.Binder binder, System.Object[ ] parameters, System.Globalization.CultureInfo culture) (at /Users/builduser/buildslave/mono/build/mcs/class/corlib/System.Reflection/MonoMethod.cs:222)
Rethrow as TargetInvocationException: Exception has been thrown by the target of an invocation.
System.Reflection.MonoMethod.Invoke (System.Object obj, BindingFlags invokeAttr, System.Reflection.Binder binder, System.Object[ ] parameters, System.Globalization.CultureInfo culture) (at /Users/builduser/buildslave/mono/build/mcs/class/corlib/System.Reflection/MonoMethod.cs:232)
System.Reflection.MethodBase.Invoke (System.Object obj, System.Object[ ] parameters) (at /Users/builduser/buildslave/mono/build/mcs/class/corlib/System.Reflection/MethodBase.cs:115)
UnityEditor.HostView.Invoke (System.String methodName, System.Object obj) (at /Users/builduser/buildslave/unity/build/Editor/Mono/HostView.cs:262)
UnityEditor.HostView.Invoke (System.String methodName) (at /Users/builduser/buildslave/unity/build/Editor/Mono/HostView.cs:255)
UnityEditor.HostView.OnGUI () (at /Users/builduser/buildslave/unity/build/Editor/Mono/HostView.cs:84)

I’m also getting a similar error when I try and use the preferences window:

MissingMethodException: Method not found: ‘UnityEditor.EditorGUI.ButtonMouseDown’.
UnityEditor.PreferencesWindow.ShowExternalApplications () (at /Users/builduser/buildslave/unity/build/Editor/Mono/PreferencesWindow/PreferencesWindow.cs:385)
UnityEditor.PreferencesWindow.OnGUI () (at /Users/builduser/buildslave/unity/build/Editor/Mono/PreferencesWindow/PreferencesWindow.cs:303)
System.Reflection.MonoMethod.Invoke (System.Object obj, BindingFlags invokeAttr, System.Reflection.Binder binder, System.Object[ ] parameters, System.Globalization.CultureInfo culture) (at /Users/builduser/buildslave/mono/build/mcs/class/corlib/System.Reflection/MonoMethod.cs:222)
Rethrow as TargetInvocationException: Exception has been thrown by the target of an invocation.
System.Reflection.MonoMethod.Invoke (System.Object obj, BindingFlags invokeAttr, System.Reflection.Binder binder, System.Object[ ] parameters, System.Globalization.CultureInfo culture) (at /Users/builduser/buildslave/mono/build/mcs/class/corlib/System.Reflection/MonoMethod.cs:232)
System.Reflection.MethodBase.Invoke (System.Object obj, System.Object[ ] parameters) (at /Users/builduser/buildslave/mono/build/mcs/class/corlib/System.Reflection/MethodBase.cs:115)
UnityEditor.HostView.Invoke (System.String methodName, System.Object obj) (at /Users/builduser/buildslave/unity/build/Editor/Mono/HostView.cs:262)
UnityEditor.HostView.Invoke (System.String methodName) (at /Users/builduser/buildslave/unity/build/Editor/Mono/HostView.cs:255)
UnityEditor.HostView.OnGUI () (at /Users/builduser/buildslave/unity/build/Editor/Mono/HostView.cs:84)

It just suddenly started doing this in all my project files and wasn’t giving me problems until tonight. Please Help!

You can’t use anything in the Editor class for builds!

So PlayerSettingsEditor is probably stripped when you try and build, guessing the same for EditorGUI. You ahve to find alternatives or wrap that stuff in #if(UNITY_EDITOR)