Troubleshooting Installation
If you encounter errors or issues while installing WHMCS, see the sections below to start troubleshooting and resolve the issue.
- For more information, see Getting Started with WHMCS and Install WHMCS.
- For general steps to troubleshoot problems in WHMCS, see Start Troubleshooting.
Installation Issues
You may encounter the following common issues:
| Error or Issue | Cause | Next Steps |
Oops! Something went wrong and we couldn't process your request. or SQLSTATE[23000]: Integrity constraint violation: 1062 Duplicate entry '1' for key 'tblconfiguration.PRIMARY' | You have initiated the installation process twice simultaneously. | Duplicate tblconfiguration Errors |
Field xxx doesn't have a default value | You attempted to install WHMCS with MySQL Strict Mode enabled. | Field Default Value Errors |
A license key is required. If you don't have one, please visit www.whmcs.com to purchase one. | There is an issue with the PHP sessions configuration in your server environment. | License Key Required Errors |
| The installation process became stuck on Step 4. | Your system or its configuration do not meet our system requirements. | Stuck Installation Process |
Updates and General Issues
- To troubleshoot display and access issues on WHMCS installations, see General Troubleshooting.
- To troubleshoot errors after updating to a new WHMCS version, see Troubleshooting Updates.
Last modified: 2025 May 7