A new maintenance release of FDS and Smokeview is available for download at
https://pages.nist.gov/fds-smv/downloads.html
Release notes can be found at
https://github.com/firemodels/fds/wiki/FDS-Release-Notes
For those of you who have been having difficulties with tunnel fire scenarios, you might want to search the new User's Guide for the parameter TUNNEL_PRECONDITIONER. This parameter has the effect of stabilizing the pressure and velocity fields in long tunnels with fires and solid interior walls.