Searching, I did not find this mentioned, so: I notice a strange behavior in cycles with all light types except directional. It looks like they are oriented wrong, or just shading strangely, but then during ApplyDynamicObjectTransforms, they appear to work correctly:
I observe this on the current 7.15.22039.13001 on windows, using either cpu or gpu, but it does not manifest for me on the current 7.15.22039.13002 on mac (running on m1 here, and only checked rectangle lights).
Opening this file with upcoming 7SRC16 has the light rendering just fine for me, as did a 7.15 build from ten days earlier than you have, 7.15.22029.15001. I haven’t made changes to lighting code for quite a while. The last change to rectangular lights was for 7.12.
Your video looks like shadow intensity gets set to 0 for unknown reason.
I’ll see on Monday if I can reproduce this, but quick tests with your file on my Windows machine says no problems.
Checked on another machine, no problem seen with 7.14.22010.17001. Updated that install to current, still no problem. So tried to get cycles running from a safe mode session without success. Finally, tried renaming the roaming profile, and the issue went away. Copied my settings into the new profile, and the issue returned. Copied those settings onto the other machine, and it also appeared there. I’ll send the settings file by private message.
