Troubleshooting Guide
You may encounter some common errors while using WHMCS. Before contacting support, run through the steps below to attempt to resolve the issue yourself.
Contents
Known Bugs
When we identify issues between releases, we publish individual patches (hotfixes) outside of the update structure. You can apply these if you are encountering issues. For solutions to known problems, see Hotfixes Forum.
Module Command/Registrar Error
Module Command Errors are error messages that third party systems return via modules. For example, you may see errors from cPanel, Plesk, Enom, ResellerClub, and other modules.
To discover the cause of errors that a third party system returns, consult the vendors documentation or support team. For lists of common errors, see:
To attempt the failed actions again, use the Module Command buttons for the service or domain within the admin area clients profile.
Unknown Errors
Sometimes a third party system or module will provide a response that WHMCS is unable to recognise and interpret. This can result in the display of an "Unknown Error" message. In these cases, you can use the System Module Debug Log to obtain the raw response, which will typically help identify the problem.
Oops!, Blank, or Partially Loading Page
When you see an "Oops!", blank, or partially loaded page, an error condition has occurred. To get more information about the error condition, enable Display Errors or check your logs as described in Error Management.
We have collated some common errors and their causes, which you may refer to in the following sections:
Payments Not Recorded
The callback setting configuration must communicate with your WHMCS installation. If it does not, the system may not successfully record payments in WHMCS.
For more information, see Troubleshooting Payment Record Issues.
500 Internal Server Error
The 500 internal server error indicates there is a problem processing the request. This is usually due to a customisation or an issue with the PHP configuration causing issues.
The first step would be to try and get further details on the error being raised. You can do this by adding $display_errors = true; to your configuration.php file or reviewing the PHP error_log file.
This should indicate which file is causing the error. If it is a 3rd party module or customization then you should remove the custom files and confirm if this resolves the error.