Just getting an error when trying to create a Feature Layer (in Content, going through Create - Feature Layer and then building a Points/Lines/Polygons Feature Layer). Get to the final stage and an error is reported.
Have also tried going into the data tab on one I created yesterday and the same error appears.
EDIT - now unable to go into the data tab on any of my Feature Layers. AGOL (and GeoNet) also keeps wanting me to sign back in.
ALSO EDIT - none of my layers are showing up on my webmap.
YET ANOTHER EDIT - everything is now going really slow. Just logging in or navigating around the Content section. I expect ESRI are having some issues.