Deferred Lighting not working properly

Hello I recently purchased Unity Pro and i was switching some things and the deferred lighting seems to not be working properly. for example if i don't use lightmaps, then the whole scene disapears...

1: Deferred lighting with lightmaps 2: Forward with lightmaps 3: Deferred lighting without lightmaps

One other problem is that the camera is rendering double the polygons in deferred lighting than with forward.

I tried to create a new scene in the project and the same thing happens, but when i create a new project, everything is ok.

I'm using some shaders created with Strumpy Shader Editor but not on all objects.

Here's another image: I created a new scene and created a plane and a spot light and this happens

Can someone say why this is happening?

Thanks