Not sure if you mean that you have got the Flagrant System Error, but if you did:
Have you tried with hitting the 'Enter' key?
That should clear it

Same thing here
It isn't Awesome, its EA I believe
Haven't you ever noticed the phone ringing around 00:06-00:008?

You get the messages that 'put a name here' is getting old and maybe you need pay to visit
and when you answer/click ignore the phone, same message with another name appears
That what happens if the game keeps working

otherwise on the first ring from the phone the game freezes
Phone sound is still playing, radio is playing ect ect
Turning the phone off, removing it from the house had the same effect

I have the latest patch en AM, removed cache files ect
Aging on, AM story on, EA story on. indo enabled but not installed (in showconfig its shows as false however, prob. because not installed)
Freq saving and praying, cause when I save at 23:59 and de game freezes and thus I kill it...
when I load the 23:59 save, there is aprox 60% change it won't happen again for that night
turning the phone off doesn't do the trick, same story
Only thing different from you Aqua is that it doesn't matter if anyone is still up
Also tested with Sims week period in a 1 person small house and with a 8 person household: same thing, when phone rings game freezes frequently