Troubleshooting Customizations

If you encounter errors or issues while working with themes, templates, or other customizations, see the sections below to start troubleshooting and resolve the issue.

You can troubleshoot some custom code using the steps in Troubleshooting WHMCS API Calls and Troubleshooting Hooks.

Hooks

During the development process, you may need to verify whether your hooks are working correctly. This can include checking whether hooks are loading properly, triggering the desired hook point, and running the expected hook code.

For steps to troubleshoot hooks in your customizations, see Troubleshooting Hooks.

Order Form Templates

You may encounter the following common issues:


Error or IssueCauseNext Steps
Pages in WHMCS are empty or content is missing.A template file is missing or contains a syntax error.Empty Pages

System Themes

For steps to troubleshoot system theme issues, see Troubleshooting System Themes.

You may encounter the following common issues:


Error or IssueCauseNext Steps
Pages in WHMCS are empty or content is missing.A template file is missing or contains a syntax error.Empty Pages
You cannot delete the active system theme.This error occurs when attempting to delete a theme that is the active System Theme.Theme Deletion Errors
The system could not create the theme.You attempted to create a theme with a name that already exists or contains invalid characters.Theme Editor Creation Errors

WHMCS API Calls

During the development process, you may need to verify whether your API code is working correctly. To do this, we recommend verifying your code against our documented code examples and enabling debugging to find errors.

For steps to troubleshoot calls to the WHMCS API, see Troubleshooting WHMCS API Calls.

Last modified: 2025 July 28