Hi,
It’s possible that the warning is harmless depending on what is happening at the moment it fires, but the scenario we’re trying to warn about is a UI softlock where focus can’t be routed properly and ends up somewhere unwanted (or somewhere it can get stuck) since that can be a big problem on platforms without a mouse. Essentially, CommonUI builds a tree and sets focus to the leafmost activated widget, which should be the widget on top of all others. When that widget is deactivated, we look for a new leafmost widget to set focus to, and that widget applies it’s own input configuration if needed to customize how input will work at that “level” of the interface. You can set LogUIActionRouter to Verbose to verify, but what is likely happening here is multiple widgets are deactivating and the router is trying to set focus to a newly deactivated widget (and failing). This is probably fine if that widget’s deactivation causes another call to UpdateLeafNodeAndConfig and the second call is successful, we send a warning in case something has gone sideways and we can’t find any valid focus target.
If you have a reliable repro case, I’d recommend enabling that logging just to verify which widget is failing to receive focus so you can confirm that the router will always be redirected to some other leaf node. If it’s an expected scenario (like deactivating multiple widgets at once) then it should be safe to downgrade the warning.
Best,
Cody