Occasionally, in Houdini (Solaris), if I try to tumble in the viewport, or adjust the view in any way, a red X appears with the text "Renderer updates are disabled". There is also white text which states "Updates to this view are disabled." and "View may be out of date"

How do I get the view port to not have updates enabled, ie, to function as expected?

I had turned Auto-Update (bottom right corner of ui) to Manual, and then later back to Auto Update. Is it stuck on Manual?

Incidentally, those two phrases (ie "Renderer updates are disabled") are among some of the only things that return no results to an internet search, so they apparently aren't documented at all by SideFx.

You may have accidentally pressed the "lock viewport stage" button. It's the Pause icon in the right-side toolbar of your viewport.

Yes, that was it. Thank you.