Steps to reproduce:
- Precondition: Zlib support in PHP is not enabled
- Navigate to Administration -> Authentication and configure SAML settings.
- Logout and try to login using "Sign in with Single Sign-On (SAML)".
From PHP log:
To solve the problem in SUSE Linux, separate package php-zlib must be installed.
When installing PHP from source, it should be configured --with-zlib[=DIR].
The error will not appear if compression of SAML requests and responses (enabled by default) is disabled using the following settings in zabbix.conf.php: