Bug report.
If you have notifications enabled under Game Options, you receive messages when buying a weapon or a module or upgrading it to a Mark 5 version in hangar.
Problem is, when you upgrade or research your weapon or module with loyalty vouchers, it will not show any notifications in hangar.
Summary:
Mark 1 - basic version - shows a notification
Mark 2 upgrade - does not show a notification (missing)
Mark 3 upgrade - does not show a notification (missing)
Mark 4 upgrade - does not show a notification (missing)
Mark 5 - final version - shows a notification