Q: The Touchstone Identity Provider encountered the following error while processing your request - Authentication failure, session missing during completion of profile handler.

• This Touchstone error prevents access to Touchstone-authenticated sites.
• Certificate-only sites such as https://web.mit.edu will still work.
• Certificate-only authentication will generally work, but Touchstone authentication using certificates (or username/password) will break.

Context

• Test Touchstone here: http://touchstone-tester.mit.edu/
• Test certificates here: http://web.mit.edu/certificates/test/

Answer

• This error shows up with the IP address of the client changes midway through Touchstone authentication.
• This can be caused by using a proxy server
• If the proxy server cannot be avoided or disabled, using the MIT VPN may help