Troubleshooting Addon Modules
If you encounter errors or issues while using WHMCS’s addon modules, see the sections below to start troubleshooting and resolve the issue.
- For general steps to troubleshoot problems in WHMCS, see Start Troubleshooting.
- For more information about addon modules, see Addon Modules.
General Errors and Issues
You may encounter the following common issues:
| Error or Issue | Cause | More Information |
Oops! | The addon module is incompatible with your WHMCS version or system configuration. | Addon Module Oops! Errors |
| An addon module does not appear in the Addons menu. | You have misconfigured file or folder permissions. | Missing Addon Modules |
cPanel Licensing
- For more information about the WebPros Partner addon module, see WebPros Partner.
- To troubleshoot issues with the license on a cPanel & WHM server, see Troubleshooting Server Issues.
You may encounter the following common issues:
E-Invoicing
For more information about the E-Invoicing addon module, see E-Invoicing.
You may encounter the following common issues:
| Error or Issue | Cause | More Information |
| Saving the E-Invoicing addon module settings returns a validation error, or the addon module displays a configuration warning. | This error occurs when a required value is empty or in an invalid format, or when you provide only one of the two license credentials. | E-Invoicing Configuration Errors |
The E-Invoicing addon module displays a License validation failed., Your license is suspended., or Validating license... license status. | This issue occurs when the license credentials are incorrect, the E-Invoicing subscription has lapsed, or the server cannot reach the e-invoicing service. | E-Invoicing License Errors |
After you save valid settings, a banner displays The system failed to synchronize the account with the e-invoicing service. | This error occurs when the license credentials are incorrect, the e-invoicing service is temporarily unavailable, or the server cannot reach it. | E-Invoicing Account Sync Errors |
An info icon appears next to a client in Client Management with the tooltip Client data is missing for e-invoicing. or The system failed to export the contact to the e-invoicing service., or the Activity Log includes a You have not enabled e-invoicing for the client. entry. | This error occurs when required client information is missing or invalid, the e-invoicing service rejects the contact, or you have not enabled E-Invoicing for the client. | E-Invoicing Client Data Errors |
An invoice does not export, or it displays Error in the E-Invoicing Status column in the Invoice Management section at Addons > E-Invoicing. | This error occurs when the invoice is not eligible for export, the system could not export the client contact, or the e-invoicing service returns an error. | E-Invoicing Invoice Export Errors |
Invoice details change after export, or you see the warning The system has already submitted this invoice for e-invoicing. | This issue occurs because the system treats invoices as immutable after it exports them to the e-invoicing service, as legal compliance requires. | Invoice Already Submitted Errors |
| An invoice exported successfully, but its e-invoicing status never updates, or webhook delivery fails with a 401 response. | This issue occurs when the License Key is missing from the addon module settings or the webhook endpoint is not reachable from the e-invoicing service. | E-Invoicing Status Update Errors |
| An invoice displays Refused in the E-Invoicing Status column in the Invoice Management section at Addons > E-Invoicing. | This issue occurs when the recipient rejects the e-invoice through their own system. | Refused E-Invoice Status |
ImportAssist
You can troubleshoot ImportAssist issues by downloading the import log at Configuration () > System Logs. When you contact WHMCS Technical Support for help with ImportAssist issues, make sure to include this log file in the ticket.
For more information about the ImportAssist addon module, see ImportAssist.
You may encounter the following common issues:
| Error or Issue | Cause | More Information |
Client import failed | The import file format was invalid, or the file contained invalid data. | Client Import Failed Errors |
Unable to connect to the database | A firewall or setting blocks remote connections from WHMCS Cloud. | Cloud ImportAssist Errors |
Import batch completed for client: Processed: 25, Failed Validation: 1, Duplicated: 0. | The data for a client was invalid in the import file. | Import Validation Failures |
Unable to connect to the database | ImportAssist cannot establish a connection to the source database to import data. | ImportAssist Unable to Connect |
Imported clients are missing or you see duplicated items in logged import results: Import batch completed for client: Processed: 25, Failed Validation: 0, Duplicated: 1. | The system does not import duplicate data. | Missing Imported Clients |
Live Chat
For more information about the Live Chat addon module, see Live Chat.
You may encounter the following common issues:
| Error or Issue | Cause | More Information |
| An unexpected connection error while attempting to log in to Live Chat. | You have misconfigured file or folder permissions. | Live Chat Connection Errors |
The requested content cannot be loaded. Please try again later. | The system cannot create the required template cache. | Live Chat Display Issues |
License Invalid or you cannot log in to Live Chat. | Your WHMCS installation has not updated to recognize your purchase of the Live Chat addon. | Live Chat Login and License Errors |
Incorrect Server/Host | The Live Help installation does not exist at the accessed URL. | Live Chat Server or Host Errors |
| You see problems when Live Chat attempts to send email using SMTP. | You have not performed all of the configuration steps to use SMTP with Live Chat. | Live Chat SMTP Errors |
Nova Cloud: Prompt First
For more information about the Nova Cloud: Prompt First addon module, see Nova Cloud: Prompt First.
You may encounter the following common issues:
| Error or Issue | Cause | More Information |
Nova Cloud: License External ID capture hook failed or Nova Cloud: Unable to store the License External ID for service | The Nova Cloud: Prompt First addon module could not read the Nova Cloud order’s status after provisioning, so it could not capture the service’s License External ID value. | Nova Cloud License External ID Errors |
The service license is suspended. Please contact support. or a similar Nova Cloud license message. | The customer’s Nova Cloud license is suspended, expired, terminated, missing, or invalid, or the system rejected the customer’s credentials. | Nova Cloud License State Errors |
Nova Cloud: Deep-link handling failed: <error> | An error occurred while the addon module was resolving the identifier that Nova returned from an upgrade or login redirect. | Nova Cloud Deep-Link Failures |
Software Licensing Addon
For more information about the Software Licensing addon module, see Software Licensing.
You may encounter the following common issues:
| Error or Issue | Cause | More Information |
Invalid Key | The licensing check code is not passing a license key back to the Software Licensing addon. | Licensing Invalid Key Errors |
| The Software Licensing addon module is generating a new local key on every request. | There is a problem when the system attempts to store the local license key. | Licensing Local Key Generation |
Remote Check Failed | There is a connection problem between the user’s server and the end client’s server. | Licensing Remote Check Errors |
Theme Editor
- For more information about the Theme Editor addon module, see Theme Editor.
- For help troubleshooting issues with theme code or customization, see Troubleshooting System Themes.
You may encounter the following common issues:
| Error or Issue | Cause | More Information |
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 |
Translation Editor
For more information about the Translation Editor addon module, see Translation Editor.
You may encounter the following common issues:
| Error or Issue | Cause | More Information |
The text that you entered contains potentially-dangerous content. Edit your text and try again. | The override text that you entered contains potentially-dangerous or malicious code that the system cannot safely save. | Translation Editor Content Errors |
Last modified: 2026 September 25