Is it possible to create content with the demo version?

Hi, I have been trying to create some custom coat mesh for my friend.

I do not own the full game so I loaded up a demo version downloaded from steam and then installed Sims 4 Studio.

Following tutorials I could export the required base meshes, created my mesh and the copied the vertex weights from the example over to my model.

On the final step I should have been able to import my model back into the sims 4 studio but I get the following error. 
I am sure that I did all the steps the same as in some tutorials and everything looks proper so the only thing I can think that is my problem is that I am using the demo version of sims.  Can anyone confirm that it is possible to make custom clothes content with the demo version of the game?

For reference there is the error code(which i know many people can not understand but there may be someone who can see the error here and know what it means. I think that the problem is what I highlighted below and that the sequence contains no elements. If someone knows what that means I would be so grateful if you could let me know.)

I have included 2 blend files, one I tried leaving the bones intact in the file and the other removed them to try but same error.
www.mediafire.com/file/wwr959vo1opvu2h/NUDE.blend/file
www.mediafire.com/file/mitxpdr20j4oafj/NUDE_test1.blend/file

And here the package for the coat in question.
www.mediafire.com/file/tjo9ss31f4uaolk/NUDE.package/file


Thank you all for reading this and helping me figure this out!

The Sims 4 Studio - Version 3.1.4.1

System.AggregateException: One or more errors occurred. ---> System.InvalidOperationException: Sequence contains no elements

at System.Linq.Enumerable.First[TSource](IEnumerable`1 source)

at S4Studio.Data.IO.CAS.CASNormalRetainer.RetainNormals(UInt64 basis_instance, IResourceProvider game_source, CASPartResource casp, IResourceProvider local_source)

at S4Studio.Data.IO.CAS.CASNormalRetainer.RetainNormals(UInt64[] basis_instances, IResourceProvider game_source, CASPartResource casp, IResourceProvider local_source)

at S4Studio.Data.IO.CAS.CASNormalRetainer.RetainNormals(CASPartResource casp, IResourceProvider game_source, IResourceProvider local_source)

at S4Studio.ViewModels.CAS.CASLODItem.ImportMesh(BlenderUtilities blender_util, String blender_path)

at S4Studio.ViewModels.CAS.CASStandalone.<>c__DisplayClass71_0.<ExecuteImportMesh>b__0()

at System.Threading.Tasks.Task.InnerInvoke()

at System.Threading.Tasks.Task.Execute()

--- End of inner exception stack trace ---

---> (Inner Exception #0) System.InvalidOperationException: Sequence contains no elements

at System.Linq.Enumerable.First[TSource](IEnumerable`1 source)

at S4Studio.Data.IO.CAS.CASNormalRetainer.RetainNormals(UInt64 basis_instance, IResourceProvider game_source, CASPartResource casp, IResourceProvider local_source)

at S4Studio.Data.IO.CAS.CASNormalRetainer.RetainNormals(UInt64[] basis_instances, IResourceProvider game_source, CASPartResource casp, IResourceProvider local_source)

at S4Studio.Data.IO.CAS.CASNormalRetainer.RetainNormals(CASPartResource casp, IResourceProvider game_source, IResourceProvider local_source)

at S4Studio.ViewModels.CAS.CASLODItem.ImportMesh(BlenderUtilities blender_util, String blender_path)

at S4Studio.ViewModels.CAS.CASStandalone.<>c__DisplayClass71_0.<ExecuteImportMesh>b__0()

at System.Threading.Tasks.Task.InnerInvoke()

at System.Threading.Tasks.Task.Execute()<---