This quote comes from OrangeMittens over at Sims 4 Studio
Hi all,
In the recent patch, EA made a change to chair code causing chairs to require 32-bit instance numbers instead of the 64-bit numbers they've always used. This change was, most likely, an unintended consequence of other changes made to chairs. I think this is true for two reasons: 1. this kind of change has occurred in the past and EA always reversed it in a later patch and 2. there is no benefit gained by using 32-bit instance numbers instead of 64-bit instance numbers. In fact, there is a drawback in that a smaller pool of possible instance numbers is more likely to result in instance number collisions (two objects with the same instance number).
Andrew has posted about the problem at EA forum. We're hopeful that they'll back this change out as they have when similar unintended consequences occurred in the past.
If they won't, Studio will add a batch fix to make existing chairs work again.
Having EA fix this is, obviously, the best outcome. A batch fix for this particular issue would cause all instances of batch fixed chairs to disappear from saved games. Further, as stated above, smaller IDs lead to a greater chance of content collision in the game.
NP. I would also like to encourage people to wait at least a little while for EA to fix this or for a batch fix to be made. If everyone starts making their own instance numbers for every chair they have, there are going to be hundreds of chairs out there each with hundreds of different instance numbers. This could cause problems down the road if people start sharing their chair folders with friends who are also receiving chair folders from other people. The instance number is what the game uses to tell which object is what. Things that increase the chance that a player will have more than one item with a given instance number or versions of the same item with different instance numbers in their game should be avoided. If we do a batch fix we can hash the number in a fashion that ensures a specific chair gets the same number no matter who batch fixes it.
