Custom controllable error - Object reference not set to an instance of an object

[amc-nu]

Hey,

I'm trying to create a custom controllable based on the TrafficCone example.
I can create and export successfully the controllable. It even worked the first time. However, after editing the model and exporting it again, now the simulator outputs the following during initialization:

found manifest at Controllables\controllable_Test\manifest 
(Filename: C:\buildslave\unity\build\Runtime/Export/Debug/Debug.bindings.h Line: 35)

failed to load asset from Controllables\controllable_Test\manifest: Object reference not set to an instance of an object STACK:   at Simulator.Web.Config.LoadControllablePlugin (Simulator.Manifest manifest, VirtualFileSystem.VfsEntry dir) [0x00054] in <c08252f04b61463890d3e3b5a919ddf6>:0 
  at (wrapper delegate-invoke) <Module>.invoke_void_Manifest_VfsEntry(Simulator.Manifest,VirtualFileSystem.VfsEntry)
  at Simulator.Web.Config.checkDir (VirtualFileSystem.VfsEntry dir, Simulator.Web.Config+AssetLoadFunc loadFunc) [0x0006a] in <c08252f04b61463890d3e3b5a919ddf6>:0  
(Filename: C:\buildslave\unity\build\Runtime/Export/Debug/Debug.bindings.h Line: 35)

Do you have any idea what could be causing this error?

Thank you for your kind support.