SymptomsPHP version 5.2 is installed on the server. You may check the PHP version with the command rpm -q. For example:
~# rpm -q php
The above output means that PHP version 5.2 is installed.
After upgrading Parallels Plesk Panel to version 9.5.2, Horde Webmail does not work correctly. From time to time, the login page is not opened via http://webmail.domain.tld. Instead, a download box is shown that offers to download the PHP script login.php.
Or, a blank page is shown when opening mail messages in Horde Webmail.
The following error is shown in the main log file of the Apache service:
[Mon Aug 23 12:56:36 2010] [notice] child pid 21575 exit signal Segmentation fault (11)
[Mon Aug 23 12:59:08 2010] [notice] child pid 26024 exit signal Segmentation fault (11)
CauseThe problem is caused by an issue in PHP version 5.2.
It is fixed in PHP version 5.3.
ResolutionAdd the following record into /etc/sysconfig/httpd on Red Hat-based distributions and to /etc/apache2/envvars on Debian-based distributions:
The following command may be used:
Red Hat-based distributions:
~# echo "export USE_ZEND_ALLOC=0" >> /etc/sysconfig/httpd
~# echo "export USE_ZEND_ALLOC=0" >> /etc/apache2/envvars