'User must first login through portal xxxxx' error when using WebDAV

Issue

• When using WebDAV with an SSO, changing the password on your Liferay account causes the digest in the User_ table to be wiped and changed to null.  
• This causes the error "User must first login through the portal xxxxx"

• [com.liferay.portal.service.impl.UserLocalServiceImpl:1314] User must first login through the portal 167725
  
   User must first login through the portal 167725

Environment

• Portal 6.2

Resolution

• Verify that all users log in using the sign-in portlet on their Liferay Site.

Additional Information

• WebDAV Support Policy