I had installed Studio to a host that was supposed to join existing cluster. install.sh picked the installation directory. It happened to be different, than installation directory used on other hosts. The "mpirun -hosts old-host1, old-hos2, new-host IMB-MPI1" hangs. Turns out all paricipating hosts have to have identical installation.
I was unable to find how to specify the installation directory.
I was unable to cleanly uninstall the previous the previous Studio version.
If a host had previous version of Studio installed, seem to affect the location of new installation.
I wanted to enable the default installation at /opt/intel, for that I wanted to clean up the host before running install.sh for new install.
Did "uninstall" option running install.sh, removed rpms, removed whole directories: sometimes it worked, other times not.