Yes I’m still having issues. The problem seems to be intermittent at this point. I have seen it come and go several times and can find no way to either make it always work or always fail.
Yesterday when I started developing, it worked at first. I was able to debug in preview mode for awhile since setting options was working, but hit a wall when selectedIndex failed in a light box. I decided to restart the editor since that sometimes clears up various problems that arise. But then the original problem came back.
I checked my simple demo and added code to test setting selectedIndex. Everything worked ok in the demo. I restarted the editor and it still worked.
I considered that since my page has a lot of code and elements I might be overwhelming the system. However, in prepping this reply just now, I went back to the demo and tried it again and it failed.
I have been forced to test live in a duplicate of the site to get the job finished which was about an hour ago.