Unable to import the demo-theme as seen in live preview.

Hi there, I had purchased this theme last morning and since then m breaking my head to get this working. I am able to install the theme, upload it onto wordpress and see it active. But here is the problem. I want a similar structure as seen in your demo-livepreview. I go to General SeTTINGS-> One click install. Everything goes as expected. Now when i hit my temporary domain. I see this beautiful site as seen in the demo. But when i navigate by clicking on any of the tabs i get this error :

Fatal error: Call to undefined function is_shop() in /home/content/p3pnexwpnas02_data03/86/2700186/html/wp-content/themes/blackfyre/header.php on line 313

I am fed-up and tired. Have spent nearly 20hrs doing this with no luck. Could you guys please help asap. I need to get this done and going. I wanted to pay that additional 50$ and make you guys do it for me. But i thought this would be pretty easy. Its really hard to do things with this theme i am feeling 🙁

Hope you can look into this on priority 🙁 Thanks

Have also attached a file for your reference.