@manton to be clear - despite the warning - ignore it and everything just continued to work - a few hours later the error warning is no longer happening - previously - drag down to refresh - error warning - ignore - works.
@JohnPhilpin This error message comes from Safari, specifically its WebKit browser engine. WebKit experienced some kind of internal error, such as a network hiccup, memory issue, or logic glitch. If you can find a way to consistently reproduce the bug, you can report it to the WebKit team over here.