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Troubleshooting PHP

WHMCS runs on PHP code and requires several PHP extensions in order to function normally. If there is a problem with PHP on your server, you will experience problems in many areas of WHMCS.

System Requirements

For successful installation, updates, and operation, your system must meet the minimum system requirements for your WHMCS version.

Install ionCube Loader

ionCube Loader® is a PHP extension that allows decoding and encoding of WHMCS files. Make sure your system uses the correct version.



Custom Template PHP

You can add PHP code to your custom templates. We recommend using the hook system for most customizations.




Fatal Memory Size Errors

Troubleshoot and resolve Fatal error: Allowed memory size of 33554432 bytes exhausted (tried to allocate 20480 bytes) errors.





Legacy Smarty Tags

To promote better security, we plan to move to Smarty 4, which is not compatible with SmartyBC, in the near future. If you use certain Smarty tags, you must remove them now.


Login Session Length

You can adjust the login session length for admins and users. WHMCS will automatically end login sessions after the set period of inactivity.



OPcache Warnings

Troubleshoot and resolve warnings about the OPcache PHP extension.