We had simplesaml_auth 4 and simplesamlphp 1.19 installed for Drupal 9 and it worked great. We had to upgrade to Drupal 10 and composer couldnt update unless everything else updated. So we upgraded simplesamlphp to 2.1 and accessing the /simplesaml/ page works fine but /saml_login/ will give us an error. The error in PHP_ERROR logs came up with
Error in simplesamlphp_auth.module: no valid "" attribute set.
I am not sure where to start looking to resolve this issue.
Closed: works as designed
4.0
Miscellaneous
It looks like a malformed config. Not sure exactly what fixed it. I am getting another error but closing this because I no longer see this error.