Error building Player because scripts have compile errors in the editor

Hi,
Searched the forums but didn't find anything about this.
I'm very new to Unity and followed one of the learning tutorials to create a very simple AR test scene.
When I try to Build it to iOS platform it stops exporting with this error message:

Error building Player because scripts have compile errors in the editor

Build completed with a result of 'Failed'
UnityEngine.GUIUtilityrocessEvent(Int32, IntPtr) (at C:/buildslave/unity/build/Modules/IMGUI/GUIUtility.cs:179)

UnityEditor.BuildPlayerWindow+BuildMethodException: Error building Player because scripts have compile errors in the editor
at UnityEditor.BuildPlayerWindow+DefaultBuildMethods.BuildPlayer (UnityEditor.BuildPlayerOptions options) [0x00242] in C:\buildslave\unity\build\Editor\Mono\BuildPlayerWindowBuildMethods.cs:194
at UnityEditor.BuildPlayerWindow.CallBuildMethods (System.Boolean askForBuildLocation, UnityEditor.BuildOptions defaultBuildOptions) [0x0007f] in C:\buildslave\unity\build\Editor\Mono\BuildPlayerWindowBuildMethods.cs:97
UnityEngine.GUIUtilityrocessEvent(Int32, IntPtr) (at C:/buildslave/unity/build/Modules/IMGUI/GUIUtility.cs:179)

I haven't created or edited any scripts whatsoever. I changed the Scripting runtime version to .NET 3.5 (found in a similar thread) but to no avail.

Any ideas on what's going on?

Thanks.