Plz Provide a solution of my problem as soon as possible.
Just trying to get some clarity on this one. Are you trying to open the page on your computer by using software? Or are you trying to upload the page into your Unbounce account?
At the moment, .unbounce template files can only be opened from within Unbounce editor. As a refresher, you can check out the upload instructions here.
Does that answer your question, Rohit?