Hm, thats an unusual location ( or maybe the wrong path?).
Try deleting it and installing it in the recommended location ( into program files )
I tried deleting and reinstalling again and I got this able() message : The Sims 4 Studio - Version 3.1.6.3
System.AggregateException: Une ou plusieurs erreurs se sont produites. ---> S4Studio.Data.IO.Package.PackageLoadException: Failed to load C:\Program Files (x86)\Steam\steamapps\common\The Sims 4\GP06\ClientFullBuild0.package ---> S4Studio.Data.IO.Package.NotASimsPackageException: Une exception de type 'S4Studio.Data.IO.Package.NotASimsPackageException' a été levée.
à S4Studio.Data.IO.Package.DBPFHeader.Read(Stream stream, IReferenceList resources)
à S4Studio.Data.IO.Package.DBPFPackage.ReadIndexTable()
à S4Studio.Data.IO.Package.DBPFPackage..ctor(String filename, Boolean cache, IPackageEntryStorage storage, IPackageResourceCache cache_storage, IPackageCompressor compressor)
--- Fin de la trace de la pile d'exception interne ---
à S4Studio.Data.IO.Package.DBPFPackage..ctor(String filename, Boolean cache, IPackageEntryStorage storage, IPackageResourceCache cache_storage, IPackageCompressor compressor)
à S4Studio.Data.FileDb.Sims4FileTable.InsertPackage(SQLiteConnection connection, Int32 gameId, Int32 priority, PackageType type, String filename, String fullpath)
à S4Studio.Data.FileDb.Sims4FileTable.InsertDLC(SQLiteConnection connection, String product, String install, String delta_path, Boolean is_reinit, Boolean load_simulation)
à S4Studio.Data.FileDb.Sims4FileTable.Init(Boolean load_simulation, Boolean is_reinit)
à S4Studio.Data.FileDb.Sims4FileTable.Init(Boolean load_simulation, Boolean is_reinit)
à S4Studio.Shared.AppModel.DoInit()
à System.Threading.Tasks.Task.InnerInvoke()
à System.Threading.Tasks.Task.Execute()
--- Fin de la trace de la pile d'exception interne ---
---> (Exception interne #0) S4Studio.Data.IO.Package.PackageLoadException: Failed to load C:\Program Files (x86)\Steam\steamapps\common\The Sims 4\GP06\ClientFullBuild0.package ---> S4Studio.Data.IO.Package.NotASimsPackageException: Une exception de type 'S4Studio.Data.IO.Package.NotASimsPackageException' a été levée.
à S4Studio.Data.IO.Package.DBPFHeader.Read(Stream stream, IReferenceList resources)
à S4Studio.Data.IO.Package.DBPFPackage.ReadIndexTable()
à S4Studio.Data.IO.Package.DBPFPackage..ctor(String filename, Boolean cache, IPackageEntryStorage storage, IPackageResourceCache cache_storage, IPackageCompressor compressor)
--- Fin de la trace de la pile d'exception interne ---
à S4Studio.Data.IO.Package.DBPFPackage..ctor(String filename, Boolean cache, IPackageEntryStorage storage, IPackageResourceCache cache_storage, IPackageCompressor compressor)
à S4Studio.Data.FileDb.Sims4FileTable.InsertPackage(SQLiteConnection connection, Int32 gameId, Int32 priority, PackageType type, String filename, String fullpath)
à S4Studio.Data.FileDb.Sims4FileTable.InsertDLC(SQLiteConnection connection, String product, String install, String delta_path, Boolean is_reinit, Boolean load_simulation)
à S4Studio.Data.FileDb.Sims4FileTable.Init(Boolean load_simulation, Boolean is_reinit)
à S4Studio.Data.FileDb.Sims4FileTable.Init(Boolean load_simulation, Boolean is_reinit)
à S4Studio.Shared.AppModel.DoInit()
à System.Threading.Tasks.Task.InnerInvoke()
à System.Threading.Tasks.Task.Execute()<---