I have been trying to get remote debugging working on one of our servers so we can share the development work on a WebAPI and I kept getting the following error message on my Visual Studio 2013 Attach to process dialog:

“Unable to attach to the process. The RPC Server is unavailable”

It turns out that all I had to do was add C:Program Files (x86)Microsoft Visual Studio 12.0Common7IDEdevenv.exe to the Firewall allow list.

I knew it had to be something with the firewall, but I was trying to discover which ports the remote debugging RPC was using so I could open them. All I had to do was add the whole process and everything worked.

Now I can happily debug the code on my server.