Bgas swopped old meter for smart meter - Veritas Burglar alarm became disab?

I have had my Electric Meter of old replaced with a Smart meter by a British Gas Engineer.At some point in either the disconnection of the old meter and the installation of the new smart unit my Veritas alarm went off [it did eventually stop] and I do not know how to reset it or identify what caused the malfunction.
The box unit that I use to set/unset my alarm has 3 illuminated 'spots' viz
No1 static red [garage door]
No2 flashing Front door]
No3 static [unset]
I shall be grateful if you can explain where the problem
is, and how I can fix it to restore my unit back to its
proper working mode in order for me to 'reset' the system

Many thanks in Anticipation