How do you suppress the map viewer beta pop-up so it doesn't appear? I know this only shows once on a cleared cache, but we want to suppress this completely using Portal 10.8.1.
You can completely disable the map viewer beta by editing the config.js file located under <Portal install directory>\customizations\10.8.1\framework\webapps\arcgis#home\js\arcgisonline.
Once opened, search for "newMapViewerEnabled" and set it to false. After saving and restarting the Portal service, you should no longer get any map viewer beta pop-ups.