As I upgraded from version 1.9.4 to 188.8.131.52 the database has not been updated. How can I force the script to update? Thank you.
You can't. You don't need to.There were no database structure changes between those versions.
ok, but why I don't see the button "Prendi" in my installation that is present if I make a new installation? I think it was a DB problem
You can only see that button if the ticket is not already assigned (Unassigned) and when you have the appropriate permission to assign tickets. (Admin Panel > Agents > Groups)