Google Mail or we better know It As Gmail Has Some Glitches . Just because They Changed Up gmail From "http" To "https" protocol many people are facing problems while attaching a document.

I Myself Got troubled by this Problem And Found Out A Simple Solution That Was to Change It Back To "
"http"

The Following Steps Guide You How to Change Google Back to "http"

Many of you Will be getting an Error Of this Kind :-
To disable or re-enable this feature in Gmail:

1. Sign in to Gmail.
2. Click the gear icon in the upper-right corner, and select Mail settings.
3. In the General tab, set 'Browser Connection' to 'Always use https' or 'Don't always use https.'
   If you've never changed the setting before, no radio buttons will be selected, even though the default is indeed 'Always use https'.
4. Click Save Changes.
5. Manually change the URL to http://mail.google.com to start accessing Gmail via http.

Please note that selecting 'Always use https' will prevent you from accessing Gmail via HTTP (Hypertext Transfer Protocol). If you trust the security of your network, you can turn this feature off at any time.