Cannot save in build mode

@doranna24  Just to be thorough, please remove the Mods folder.  I've seen at least one person say that disabled mods somehow still had an effect, and it's a simple test.

If that doesn't help, does this happen no matter where you build, or only on certain lots or when using certain builds from the Gallery or your library?  Please test if you haven't already.

If this happens on any lot, even a blank one, in your main save, please test a new save, for comparison's sake, and still with the Mods folder removed.