In the June 2017 release of ArcGIS Online, Web AppBuilder was listed as now being able to consume Vector Tile Layers in the Basemap Widget. I have tried to add a vector tile layer that I published from ArcGIS Pro to WAB online version and get an error (see image below). Has anyone gotten this to work successfully with a vector tile layer created in Pro? I am currently running ArcGIS Pro 1.4.
I received the following response in regards to the bug.
The status of Esri BUG-000106317 - When adding Vector Tile Basemap in Web AppBuilder Basemap Widget an error "This type of layer cannot be used as a basemap." will appear. - that you have been associated with has been changed to Not in Current Product Plan.
Public Explanation: At this time the only supported vector basemaps in the WAB basemap widget are the Esri default basemaps. If using a custom basemap it must be a raster, not vector, basemap.