Game crashes during saving when trying to build a second story

Since I installed Seasons, it has been impossible to build a second story onto a house. Whenever I do, the game crashes during saving. Every single time I try to add a second story. I've tried spiral and straight stairs. Happens on a house built on ground level in Lucky Palms, and on an EA built trailer in Riverview.  I now have University Life (so have all expansions) but they have not addressed this bug. I'm patched to 1.50. Computer drivers are fine & up to date, and the system only uses 60-65% of my ram when the game runs. The houses didn't have holiday lights on them when trying to add the second story. The Riverview game I just started because my Lucky Palms one got corrupted, and winter is disabled there.

This is definitely a bug in the game, but there is no longer a tech support email address for contacting EA, so hopefully they check here.