scoring the housecard/christmastree

[Hollandiase]

I really do not understand why I sometimes do not score with this card. I have a cross at the end. And the endresult says -100.
And I can not find any particular rules for this board.
Neither I can find rules for the christmastree. Where can I find those rules?

[ilares]

christmas details: https://lumberjacks-studio.com/en/xmastrek/

https://lumberjacks-studio.com/en/trek-12-at-home-w1/
for the house/pandemic map, everything is explained on it, you can't put a "sad smiley face" from x, so any x result that goes over 12, for instance 4x4, otherwise you instantly lose