Dear opensuse list users, I already sent this email to the horde users mailing list. But I just thought that opensuse list might for sure also be a good place to perhaps receive some hints or insights on this topic. I'm running an opensuse 15.4 box with PHP-FPM 7.4.33 (yes I know it's EOL) Horde is 5.2.23 with IMP 6.2.27 PEAR Horde is installed at /usr/share/php7/PEAR/ php.ini sets the include path = ".:/usr/share/php7:/usr/share/php7/PEAR" as far as I know the delimiter : separates the different include paths so I have 3 paths . the current directoy /usr/share/php7 /usr/share/php7/PEAR and from what I remember PHP automatically tries to look for included files in all those 3 include paths. PHP looks first in the current directory for the file. Then the second path /usr/share/php7 and after that the third path /usr/share/php7/PEAR If I run Horde & IMP with the default php.ini include path I receive a Fatal Error Class 'PEAR_Config' not found If I then set a different path order via php-fpm pool configuration the fatal error is gone I move the PEAR path before the php7 path php_value[include_path] = ".:/usr/share/php7/PEAR:/usr/share/php7" But I still don't get it. Isn't PHP supposed to look at all given include_path one after the other? If anyone could share some insights I would be more than grateful 😄 thanks & greeetings Becki