Ho provato alcune delle soluzioni pubblicate altrove nel forum di supporto, una sembrava funzionare, ma dopo un aggiornamento di Steam mi sono ritrovato al punto di partenza, sono un nuovo utente Linux e sono già in una curva di apprendimento :) Grazie per l'aiuto
Reading package lists... Done
Building dependency tree
Reading state information... Done
Some packages could not be installed. This may mean that you have
requested an impossible situation or if you are using the unstable
distribution that some required packages have not yet been created
or been moved out of Incoming.
The following information may help to resolve the situation:
The following packages have unmet dependencies:
libgl1-mesa-glx:i386 : Depends: libglapi-mesa:i386 (= 10.1.3-0ubuntu0.3)
unity-control-center : Depends: libcheese-gtk23 (>= 3.4.0) but it is not going to be installed
Depends: libcheese7 (>= 3.0.1) but it is not going to be installed
E: Error, pkgProblemResolver::Resolve generated breaks, this may be caused by held packages.
Press return to continue: