Unable to sign in to the ArcGIS Survey123 website

Description

When signing in to the ArcGIS Survey123 website, the page loops continuously or fails with an error.

Error:
You need an ArcGIS Online subscription account to try ArcGIS Survey123.

Cause

The sign-in attempt is performed with an ArcGIS Online public account. A public account can be identified by the missing Organization tab in ArcGIS Online.

Solution or Workaround

Sign in to the ArcGIS Survey123 website with credentials of an ArcGIS Online organizational account. If the user has an existing organizational account but forgets the username, click Forgot username? in the ArcGIS Online sign-in page. The user then receives an email with the information of the organizational account and its administrators.