Does not work for me 
I did try to delete the binaries, build and intermediate folders and generate again. But still got this in vs:
Error occurred while restoring NuGet packages: Bibliothèque non inscrite. (Exception from HRESULT: 0x8002801D (TYPE_E_LIBNOTREGISTERED))
1>------ Build started: Project: CustomGravityProject, Configuration: Development_Editor x64 ------
1>The operation cannot be completed because BeginBuild has not yet been called.
1>The operation cannot be completed because BeginBuild has not yet been called.
========== Build: 0 succeeded, 1 failed, 0 up-to-date, 0 skipped ==========