Re: Having a problem with diagonal walls after the update.

@Bluebellflora Oddly, in the case of the build I mentioned, even with MOO enabled it deleted those two images, the two blank (debug) canvases in that corner, and one blank canvas in the living room (which was right up against the wall edge), but all of the other blank canvases on the other windows remained, from what I could see at a quick look-over. I re-checked, and placing with MOO disabled appears to give the same result.
Edit: I found on further testing that I could get it to place as before with MOO on. Activating MOO may be a good workaround, then, for certain changes in wall dynamics. 

@SheriGR I just saved one of my problem rooms and placed it on another lot, and it also deleted the art on the diagonal wall. Super annoying

@SheriGR 

I enabled MOO and downloaded and placed your lot in build mode, no sim on the lot, and the pictures are on the lot. At least, the same pictures as in your screenshots above. 

@Bluebellflora  I found on further testing that I could get it to place as before with MOO on. Activating MOO may be a good workaround, then, for certain changes in wall dynamics.