Using QGIS 2.12, I successfully add basemaps via Web > OpenLayers plugin.
However, if I save the project (EPSG:3857) and later reopen it, the OpenLayers basemap will not display. As a workaround, if I delete the "blank" basemap from the table of contents and then add it again via Web > OpenLayers, the basemap will display correctly. However, this must be redone every time I reopen the project.
This problem is not a show-stopper, but it is aggravating. Has anyone else experienced this oddity?