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
If the system hasn't recorded a payment in WHMCS, check the callback setting configuration on your payment gateway's website. It must be able to communicate with your WHMCS installation. As a rule, the system should send callback commands to the appropriate file in the /modules/gateways/callback directory. You can find specific instructions for individual gateways in Payment Gateways.
If the configuration is correct, navigate to Billing > Gateway Log and review the debug data at the time of payment. This should display an error message or code, which your payment gateway's documentation or support team will be able to explain. For some of the most common errors and their causes, see Payment Gateways.
If there is not a log entry and you are using a merchant gateway, this may indicate that the client has no card details on file.
In other cases, it indicates that your gateway is unable to communicate with the callback file on your server. A server setting such as the firewall or mod_security could be blocking them. For help with this, contact your payment gateway and server administrator.