[closed] JOSM: Data Layer not showing up.

I have been doing some editing, but the Data Layer has somehow disappeared from the layers sidebar. I had previously opened an old session with an outdated Data Layer, deleted the layer, and downloaded new data.

It won't let me upload or save. What is going on?

EDIT:

I believe I have found the error. Deleting the original data layer and downloading new data has actually merged the data with Roads.shp.