Android Build dll not allowed

In my app development I thought it time to put a build on the tablet and see how/if it works.

Ended up with an error and no apk file.

ArgumentException: The Assembly System.Configuration is referenced by System.Data (‘Assets/Plugins/SQLiter/DLLs/System.Data.dll’). But the dll is not allowed to be included or could not be found.
UnityEditor.AssemblyHelper.AddReferencedAssembliesRecurse (System.String assemblyPath, System.Collections.Generic.List1 alreadyFoundAssemblies, System.String[] allAssemblyPaths, System.String[] foldersToSearch, System.Collections.Generic.Dictionary2 cache, BuildTarget target) (at C:/buildslave/unity/build/Editor/Mono/AssemblyHelper.cs:156)
UnityEditor.AssemblyHelper.AddReferencedAssembliesRecurse (System.String assemblyPath, System.Collections.Generic.List1 alreadyFoundAssemblies, System.String[] allAssemblyPaths, System.String[] foldersToSearch, System.Collections.Generic.Dictionary2 cache, BuildTarget target) (at C:/buildslave/unity/build/Editor/Mono/AssemblyHelper.cs:162)
UnityEditor.AssemblyHelper.FindAssembliesReferencedBy (System.String paths, System.String foldersToSearch, BuildTarget target) (at C:/buildslave/unity/build/Editor/Mono/AssemblyHelper.cs:194)
UnityEditor.BuildPlayerWindow:BuildPlayerAndRun()

Changed the dotNet to 2.0 from subset, but made no difference.

Error building Player: Extracting referenced dlls failed.
Got one of these too…

Any thoughts?

Probably you need to inlude all referenced DLLs into the unity project. Put it in Assets/Plugins folder.

Forum thred:
http://forum.unity3d.com/threads/system-data-dll-issues.62454/