Mandar, please hold dow the CTRL key when you select preview.

Did this fix the problem?

The only single column layout you should see either online or preview is for mobile view.

Thanks.

I tried by holding CTRL key, but no change. 

Is there any other way?

Or is there any mistake by me while designing a page layout?

Please guide.

Regards

Mandar

Hello Mandar,

try to delete the file of your site on the your server provider. Then re-export the site completely.

Let me know.

Mandar, if the problem is only visible locally (offline in preview) and clearing the cache doesn't fix it then yes I suspect you "broke it".

Can you restore a backup or perhaps import your most recent iwzip? (this will not overwrite your existing project).

PS if you do not have multiple iwzip files to fall back on, one day there will be tears! (step 5 export project)

HOWEVER

Based on your screen shot, you do not appear to be looking at the project in desktop resolution, if your were the top line would be red. Have you perhaps changed the minimum resolution for desktop view to a value greater than you screen width?

And/or changed the line breaks in responsive settings?

Thanks dear Esahc...

I'll see it as per your suggestions. 

Regards

Mandar