What happens when advanced ice is derezzed (emergency shutdown). Are the advancement tokens lost? And what about ice like tyrant which can 'only be advanced when rezzed ' does that lose the tokens? i can't seem to find anything in the FAQ! perhaps I 'm just blind…

All the tokens stay in both situations that you outlined.

Ser Folly said:

Advancement tokens stay.

Ones like Tyrant and Woodcutter, that can only be advanced while rezzed that are shut down with this card simply can't be advanced further until after you come across your next opportunity to rez them.

Unrezzed ICE are still installed, so they keep all their counters. They also keep any hosted Parasite (but since they have no strength while unrezzed, the Parasite just sits there accumulating virus counters)

Thanks, I imagined that much, but that criminal mastermind opposite me, who was fairly annoyed with my Weyland ICE advanced 9 times, thought it must be otherwise, so I just wanted to check.

Ah, the magic of wishful thinking ~