Hi Fiorenza,
The only difference we can see, is that if I give the command "type
libreoffice5.2 on the working account, I see "hashing done on
libreoffice5.2 (/usr/bin/libreoffice5.2)".
If I give the same commando the NON WORKING account, I see:
libreoffice5.2 is /usr/bin/libreoffice5.2.
The behaviour isn't the same !
What does mean "hashing done" ? Perhaps is this the problem ?
At a guess, the DEB package that points to /usr/bin/libreOffice5.2 is
hashed for installation security reasons (part of the signing of the
packages) and this hash is verified when a user attempts to execute a
program from that link.
In the non-functional user accounts, the hash isn't verified, so the
application isn't executed (I'm just speculating here, don't take my
word as gospel).
This kind of rings a bell as a Ubuntu bug I read about a while ago where
some user accounts when created did not have an appropiate set up of
executable links to libreoffice - some kind of problem with /etc/skel
not copying everything or setting correct permissions for the newly
created user.
Perhaps you might find something by searching in the Ubuntu launchpad
bug database ?
Alex