18 months ago I built a SSO application according to the instructions in this tutorial - using the code on GitHub as a template. It worked fine until yesterday.
I have determined that I am getting a valid token, but the call to $token→validate() (line 32 of the sample index.php code) is returning false anyway.
I have not made any intentional changes to my environment. I'm not sure what to look at.
Any suggestions would be appreciated.