Finding no other clues, I searched the error log file. And found that it is not getting the path for the temporary folder and log folder of joomla. The path was not correct.
I have changed the path and now it is working correctly.
See the book OpenCart 1.4 Template Design Cookbook.
See the book Joomla Mobile Development Beginners Guide
List of my works:
- Product Based Quantity Wise Shipping: Find it here.
- OpenSSLCOMMERZ: integrate SSLCOMMERZ with opencart: Find it here.
- Fine Search v.1.0 - Improves Opencart search feature to find relevant: Find it here.
- Opensweetcaptcha - An easy way to generate attractive captcha for your system!: Find it here.
- Custom Field Product - add unlimited custom fields to the product form: Find it here.
- Formcaptcha - add captcha on the register page: Find it here.