Troubleshooting vTiger CRM Install on PHP 5.2

I recently had to deploy vTiger CRM 5 on a machine running PHP 5.2. Turned out that vTiger does not like PHP 5.2 because of some differences between PHP 5.0 and 5.2. As soon as you start the install script, you get the following error:

[sourcecode lang=”bash”]
Cannot redeclare class DateTime

The problem is that vTiger defines its own DateTime class and so does PHP 5.2. The solution therefore (see vTiger wiki) was to rename the class in vTiger source. To do that, all you need to do is to run the following commands from the vtiger source root (e.g. /var/www/html/vtiger):

[sourcecode lang=”bash”]
mv modules/Calendar/Date.php modules/Calendar/Date.php.back
sed s/ DateTime/ com_vtiger_DateTime/ < modules/Calendar/Date.php.back > modules/Calendar/Date.php
mv modules/Calendar/Appointment.php modules/Calendar/Appointment.php.back
sed s/ DateTime/ com_vtiger_DateTime/ < modules/Calendar/Appointment.php.back > modules/Calendar/Appointment.php
mv include/utils/RecurringType.php include/utils/RecurringType.php.back
sed s/ DateTime/ com_vtiger_DateTime/ < include/utils/RecurringType.php.back > include/utils/RecurringType.php

This script modifies the files Date.php, Appointment.php and RecurringType.php by first taking the backup of the file and then replacing all occurrences of “ DateTime” with “ com_vtiger_DateTime”. The backup is kept in the same location.

After that, you can run the install script and get to the login screen. When you login, you get a new error (something to this effect):

Catchable fatal error: Object of class <ClassName> could not be converted to string in /var/www/xxx on line yyy

The solution of this came from this great post. You need to create a custom error handler (called ErrorHandler.php) in the vtiger source root with the following content:

[sourcecode lang=”php”]
function compatibilityErrorHandler($errno, $errstr, $errfile, $errline)
switch ($errno) {
echo “Unknown error type: [$errno] $errstr n”;

// set to the user defined error handler
$old_error_handler = set_error_handler(“compatibilityErrorHandler”, E_RECOVERABLE_ERROR);

Finally, you need to include this error handler through the For that, execute the following commands:

[sourcecode lang=”bash”]
sed “/include(‘vtigerversion.php’);/ a
require_once(‘ErrorHandler.php’);” < >

Notice the line break after the a. The first command makes a backup. The second inserts the require_once directive after the line with the include directive.