A recent upgrade to PHP 5.2.5 caused a problem with Plesk/Horde webmail. Specifically:
Warning: require_once(Horde/String.php) [function.require-once]: failed to open stream: No such file or directory in /usr/share/psa-horde/lib/Horde/Browser.php on line 4
Fatal error: require_once() [function.require]: Failed opening required ‘Horde/String.php’ (include_path=’/usr/share/psa-horde:/usr/share/psa-horde/pear:.’) in /usr/share/psa-horde/lib/Horde/Browser.php on line 4
The problem is sorted with but this may need to be done each time Plesk is updated:
Amend /etc/httpd/conf.d/zz010_psa_httpd.conf from:
php_admin_value include_path “/usr/share/psa-horde:/usr/share/psa-horde/pear:.”
to:
php_admin_value include_path “/usr/share/psa-horde/lib:/usr/share/psa-horde:/usr/share/psa-horde/pear:.”
This will need to be done several times throughout that file.
Alternatively it may be better to create a new file
vi /etc/httpd/conf.d/zz010_small_horde_fix.conf
with the following contents:
<DirectoryMatch /usr/share/psa-horde>
php_admin_value include_path “/usr/share/psa-horde/lib:/usr/share/psa-horde:/usr/share/psa-horde/pear:.”
</DirectoryMatch>
This file will not be overwritten periodically so horde should not break in future.