TheoTown

If you try to use the view tool and select happiness the game crashes and deletes the town.

Yes it does crash. Haven't had it delete the town though. It is still there to be reloaded.

I did some more testing, the city is deleted only if it was not saved, so if it's a new city, it's going to be deleted, if you saved the city, it's just going to crash and start from the last save.

It doesn't do anything if you haven't built anything yet

Hmm... you are right, so it might be from the calculations made when it needs to show something?