Missing the config for sp_cert_folder. This creates an error logged that the users can see right after logging in via saml. Also missing is the certFingerprint config. These settings were removed in the latest version of samlauth.
Add default logic. To test for this and either remove that setting from the settings array or set a default value.
2.0
Code
Not all content is available!
It's likely this issue predates Contrib.social: some issue and comment data are missing.