Getting "Shader Debugger is not Available" error message in Shader List

Hello everybody, I’ve been having some trouble trying to use NSight for Visual Studio to debug some shaders. I’m new to this tool so I created a simple D3D11 project with a simple VS and PS to display a box just to try it out. The program itself is fine, but when I want to try the Shader Debugger, I can only see the compiled shader bytecode instead of the original shader source. I’ve been reading through the documentation (which links I pasted for reference) and I did all the steps relevant for getting the debugger to work but to no avail. This is what I do:

  1. Start Graphics Debugging
  2. Capture a frame using the option on the HUD
  3. Then go to NSight->Shader List and the Symbolics Status column reads "Shader Debugger is not available" for both shaders

I’m using a GeForce GTX 750 Ti (Maxwell architecture) which according to its “Supported GPUs List” it is supported by NSight 4.0. I submit pre-compiled shaders (using D3DReadFromFile) to my program, which I compiled with the built-in Direct3D Shader Compiler using the following flags: /Gfp /Zi /Od (as specified in the documentation). I also make sure that the Force Assembly Debugging flag in the NSight Options is set to ‘false’ and that my application does not use the D3D11_CREATE_DEVICE_DEBUG flag (because NSight complains about it). Can somebody kindly explain me what I am doing wrong and what is the proper way to debug HLSL shaders in NSight 4.0?

Here are the links that I checked already trying to fix this problem:

Shader Debugger documentation:
http://docs.nvidia.com/gameworks/index.html#developertools/desktop/shader_debugger.htm

NSight Basic Host Configuration:
http://docs.nvidia.com/gameworks/content/developertools/desktop/host_basics.htm#Force_Assembly_Debugging

NSight Visual Studio Edition Supported GPUs:
https://developer.nvidia.com/nsight-visual-studio-edition-supported-gpus-full-list

Thanks in advance.