For step 5, once you are on that Remote Analysis, select specify username/password, then put in your Windows credentials used to login on the remote machine that you connect to via Ansoft RSM. You may need to specify the domain as well. This can be found from Windows by right click on 'This PC' -> Properties
For step 6, I'd recommend to not do it from the GUI because that would apply only to you (your user account). If you modify it in this file C:Program FilesAnsysEMAnsysEM###Win64configdefault.cfg , it will apply to all. But if you are the only one using this, then the GUI is ok too. Yes, I had to put space otherwise this forum changes to the smiley. The one without space is correct. I'm not sure what is done in the back-end that requires the path to be Unix style.
Yes, this is generic MPI error message. For MPI communications , they are always between compute (solving) nodes, so you will need to open ports between these nodes/machines. There is an MPI test command that you can try. You can start by just including two compute nodes first. Run the following command locally from one of the solving
"%MPI_ROOT%binmpirun" -hostlist localhost:2,