The screening widget will not instantiate in WebApp Builder 2.12 Developer Addition. I called Support, working on getting a NIM. I tried plain vanilla hosted online ArcGIS Online with a service from a 10.6.1 server and same thing, Screening widget will not work. I do no configuration, just leave it as-is so when it comes in it has all the fields. Left everything default, but will not start up in the new WAB. It was working however in 2.9 WAB DE. I want to use it to have a sweet printout for parcels. For that it's perfect. Anyone else have success getting Sreening Widget working on WAB 2.12?
Example app: https://sagis.maps.arcgis.com/apps/webappviewer/index.html?id=8fa594068d7c422eab9eaece45424610