Just wanna add to the Firefox comment and is unrelated to this problem but related to voting - I'm not sure what causes that issue. I have found aftet having regenerated the map a couple of times that if it works on that map configuration when using firefox - it always does and if not, it always doesn't. It's odd. Seems unrelated to Antivirus weirdly as I originally theorised that it would be related to that.
looking at it you can see the offers are still lit as if there is items in storage but they are not visable to the player as stored. If i was to add more items to storeage it wipes the current storage and offers become unavailable.
Rooves (plural of roof) - but yeah that sounds awesome! I hadn't even thought of that :P Making it less efficient, maybe give the items inside a bit more of a worn over time feel through the rain and cause you to have longer times to build items even if you're trained in them.
EDIT: I'm going to add that in the suggestions (and give you credit).
EDIT: Added new graphic at top of post.
As NBT said, if you go inside the house and place another wooden block on the inner layer, then it converts it into a roof. It's because it needs something to affixiate to to become a roof, like stairs rather than a diagonal line.
I don't know if it's related but this issue never appeared for me until we tried to dispose of stumps on the server. When we got rid of 3 stumps on the server, this line 'Object reference not set to an instance of an object' appeared three times in the server log and eventually kept reproducing and doing so until the server disconnected.