Drupal 6, Fatal error: Cannot redeclare class view in /var/www/html/mysite/profiles/drupal_commons/modules/contrib/views/includes/view.inc on line 19

I had a working website in Drupal 6 and with PHP 5.3.5. But after updating my PHP version to latest one in Ubuntu 14.04, my website stopped working and started throwing issue like:

"Fatal error: Cannot redeclare class view in /var/www/html/mysite/profiles/drupal_commons/modules/contrib/views/includes/view.inc on line 19"

I tried to check my view.inc file and also checked for another declaration of the class but there was no problem of redeclaration.

After some goggling I found that this problem is related to Xcache and Opcache. I also tried to disable these from *.ini files but these are required for some other projects like for Drupal 8 (However these changes didn't solve the problem).

After few more searching I found a better way, which is to update .htaccess file and it worked perfectly. So just add following lines to your project's .htaccess file:

<IfModule mod_php5.c>
  php_value xcache.cacher Off
  php_value xcache.size 0
  php_value xcache.stat Off
</IfModule>

After this change, my site started working. However there were more problems related to some modules and caching setting but I was able to resolve these because I was able to access my site and admin setting pages.