keithcurtis said: You are not missing anything. This has been brought up in several other threads. The API for setting up windows has always been based on exploiting a bug in Dynamic Lighting, and the trick was known to be built on shaky ground. With the advent of one-way walls, that bug was fixed (it essentially kept certain paths from closing completely, letting tokens do an "end run" around some shapes. That's the bad news. Not unexpected, but still not an ideal development. The good news is several-fold. First off Windows are currently next in development for DL. So this situation should be temporary. Also, the one way walls give new opportunities that were not possible before, even with windows, such as columns or tree trunks which block sightlnes, but can still themselves be seen. Finally all these things (plus eventually user-controllable doors) are or will be concurrently available for Plus users, who have never been able to use such things. So slight setback in the temporary loss of an accidental feature, but big advancements either here or coming Thank you for the reply. I did look for other threads before creating this one, but I must have overlooked them. Are you aware of any workarounds that have been proposed? I'll try looking again tomorrow, but perhaps a bunch of one-way walls grouped together that could be moved to a different layer depending on if the token is inside or outside of a window?