If a 404 error page appears when you are trying to log in to the portal, this can be due to a telephone number being entered into the Homepage URL field. Contact your Head Office or Superuser to remove this to allow you to log in. If you have access to Organisation Administration area to access Users. Follow the below to remove.
Go to the Admin Cogs
icon.Click on Organisation Administration tab.
Click on Users tab.
Click on Edit on relevant User.
On the Details tab scroll down to Homepage URL [?] remove telephone number
Click Update.