I see the following warning in my log, and I don't know what I'm supposed to do.
octoprint.settings - WARNING - DeprecationWarning: Detected access to deprecated settings path ['webcam', 'stream'], returned value is derived from compatibility overlay. Please use the webcam system introduced with 1.9.0, this compatibility layer will be removed in a future release.
Currently I have a camera connected to another computer (not my OctoPrint computer) and am streaming to OctoPrint (running on 188.8.131.52).
The two plugins that might be the cause of the issue are Sidebar Webcam and UI Customizer. I know UI Customizer is working on a fix for their plugin, but not sure if Sidebar Webcam is. Technically you don't even need that plugin if you are using UI Customizer because it includes a webcam widget that you can put into any of the columns/sidebar.
In general, warnings in logs are not expected to be read by end users as 'action required'. We don't expect users to watch the logs (& vast majority don't know what they look like) to find out what they have to do on their OctoPrint installs. If action is required, it comes through the UI. So generally, don't worry about not being sure what you're supposed to do from the logs until you have an actual problem and you're trying to work it out.
The control tab is built in to OctoPrint and has been updated to use the new API with the 'Classic Webcam' plugin, because it is part of said webcam changes . If you install more than one 'Webcam Provider Plugins' it starts to show UI to select between them.
I did a search through the OctoPrint source quickly and did find one line tucked away that referenced the old setting, so perhaps that is triggering the warning message & does need updating - but again that's something for developers, not end users. So in the end, thanks for bringing it up - a test in safe mode would of course rule out the plugin issues straight away to be sure I've got it right, and so please always fill in the template that asks these questions in the first place