Problem: The login page for Portal for ArcGIS appears blank
When attempting to log in to Portal for ArcGIS, users are sometimes unable to do so because the home page (https://webadaptor.domain.com/arcgis/home/) appears blank.
This issue occurs when an expired esri_auth cookie is supplied by the browser. This is common when the token expiration value is set to a very short time in the ArcGIS REST API.
Solution or Workaround
Below are some recommended options for resolving this issue.
Clear browser cache and cookies
Increase the token expiration value