Blank page after payment on checkout success page – OpenCart CCAvenue extension issue

I wanted to use CCAvenue payment gateway on my store so I registered with CCAvenue and download OpenCart extension form their site. There were two options for this extension, first was for OpenCart version 2+ and other was for 1.5+. My store was on OpenCart 1.5.4 so I download second one and installed on my store.

After installation I configures all the information from my CCAvenue account and when I tried to place an order I was successfully redirected to CCAvenue payment page from my store but after payment I was redirect on a blank page of my store instead of payment successful message. I check in admin and found that payment status was update for the order so the issue was only correct message was not displayed to the customer. Keep on reading