Microsoft SharePoint or Teams Error - User Not Found in the Directory

This can occur if the resource was initially accessed with another account or the cached credentials are corrupt.  This is more likely to occur if accessing another organization's SharePoint or Teams site as an external user.

SharePoint and Teams web version

• Log out of SharePoint / Teams.
• Clear browser cache. 
  • Open a browser window. 
  • Enter Ctrl-Shift-Delete to launch the clear cache window. 
  • If using Chrome, leave "all time" selected.
  • Click on Clear Now or Delete.
• Close ALL browser windows and try accessing the resource again.

Teams - installed app

• Log out of Teams and close the Teams app.
• Clear cached credentials from Credential Manager.
  • Using the search field next to the Windows icon at the bottom-left of your screen, search for and launch "credential manager."
  • For both options (Web credentials and Windows credentials), remove all Microsoft and Teams related entries.
• Launch Teams and login with your UTRGV credentials.  The login prompt may be hiding under the "Loading Microsoft Teams" message window (hover over Teams icon in the taskbar to find it).​