New tab extension showing extension url in address bar

Add-ons Development
#1

I recently created a new tab add on. The add on works fine. However, the address bar will display the add-on url like this:

moz-extension://c4c10ead-23ef-4aaa-8d33-7aa1f329ce9c/#/

I check other new tab add-on and their address bar remain empty.

Anyone have clue why this happen?

My add-on: https://addons.mozilla.org/en-US/firefox/addon/pin2me/?utm_source=addons.mozilla.org&utm_medium=referral&utm_content=search