I'm new to the world of GIS, and a little confused as to why I'm getting the error ' Spatial reference does not match data frame'. The data frame and the layer(s) that I want to edit are in the same coordinate system (GCS_WGS84), but this error still pops up. So I tried to play around and start a new map where I am using just two layers (that according to their properties have the same coordinate system) and a base map from ArcGIS online. I noticed that the way the base map is displayed is different depending on which layer I pull in first from ArcCatalog, (even though they have the same coordinate system.) Could this be the reason? (and more importantly, will it have an effect on editing these layers?) Also why and how do you get the base map to display differently for the same coordinate system? (As I would prefer to have the base map with the ocean surrounding the landmass, not the base map where half the ocean is displayed on the other side of the screen.) I have attached images to show what I mean.
Any help with this would be much appreciated!