Hello Flavio!

20 Feb 17 11:43, you wrote to all:

 FB>         I am trying to install MBSE into an Ubuntu system.

 FB>         I have installed all the packages recommended at
 FB> README.Ubuntu, then I tried to execute the Setup script.

 FB>         I am getting the following error message:

 FB>         "Adding group 'bbs', user 'mbse' Linux useradd: group 'admin'
 FB> does not exist"

 FB>         What should I do now?

Which version of MBSE are you using?  There was a fix for this made in 
v1.0.6.8.

Andrew

--- GoldED+/LNX 1.1.5-b20161221