Error accessing admin of opencart after move to new server

A common issue!

When you move an OpenCart store to a new server, you may encounter issues accessing the admin panel. Here are some common causes and solutions to help you resolve the problem:

  1. URL changes: Make sure the URL of your admin panel has not changed. Check the config.php file in the root directory of your OpenCart installation to ensure the url variable is set correctly.
  2. Server configuration: Verify that the new server has the same PHP version, settings, and extensions as the old server. OpenCart may not work correctly with different PHP versions or configurations.
  3. Database connection: Check the database connection settings in the config.php file. Ensure the database host, username, password, and database name are correct and match the new server's configuration.
  4. File permissions: Verify that the file permissions for the OpenCart installation are correct. Make sure the admin directory and its contents have the correct permissions (e.g., 755 or 777).
  5. Cache clearing: Clear the cache by deleting the system/cache directory and the config.php file. This will force OpenCart to regenerate the cache and may resolve any issues.
  6. Session settings: Check the session settings in the config.php file. Ensure the session.save_path is set correctly and the session.gc_maxlifetime is set to a reasonable value.
  7. SSL/TLS issues: If you're using SSL/TLS, ensure the certificate is installed correctly and the server is configured to use it. You can try accessing the admin panel using HTTP instead of HTTPS to rule out SSL/TLS issues.
  8. OpenCart version: Verify that you're using the same OpenCart version on the new server as you were on the old server. If you've upgraded or downgraded OpenCart, this may cause issues.
  9. Third-party extensions: Check if any third-party extensions are causing conflicts. Try disabling them one by one to identify the problematic extension.
  10. Server logs: Check the server logs for any errors or warnings related to OpenCart. This can help you identify the root cause of the issue.

To troubleshoot the issue, you can try the following:

  1. Access the admin panel using a different browser or device to rule out browser-specific issues.
  2. Check the OpenCart logs (located in the system/logs directory) for any errors or warnings.
  3. Enable debug mode in the config.php file to display more detailed error messages.
  4. Try accessing the admin panel using the index.php file directly (e.g., http://example.com/admin/index.php) to bypass any routing issues.

If none of these solutions work, please provide more details about your OpenCart version, server configuration, and the exact error message you're seeing, and I'll do my best to help you resolve the issue.