Suddenly, I am no longer able to see ANY of my data on the chart tab. It had been working just fine. The data is all there on the Data tab, it just is refusing to draw anything on the Chart. This is observed using the same Chrome browser/Windows7 PC I've used all year, and is also visible on my Android mobile devices in their Chrome browsers. I have been getting a LOT of "502 Bad Gateway" messages, as well as the browser page failing to update. Usually, reloading the page fixed it. But not anymore.
Any suggestions to fix this are welcome.