After upgrading to LoadRunner 9.x I started getting a window popup which said “Failed to connect to server” every time I opened virtual user generator (vugen.exe).
The solution to this was to close virtual user generator and delete the [vugen.ini] file.
vugen.ini is found in the %systemroot% folder on your Windows PC (usually C:WINDOWS or C:WINNT).
Once you’ve deleted the file, virtual user generator will open without any issues and create a new vugen.ini file automatically.