Hi versam, what happens when you go to either of these addresses?

https://www.hotmail.com/

https://outlook.live.com/owa/

Usually those will both redirect to a sign-in page:

https://login.live.com/login.srf

And then after you sign in, you will be sent back to your Inbox. Where is this process failing for you?

More generally... When you have a problem with one particular site, a good "first thing to try" is clearing your Firefox cache and deleting your saved cookies for the site.

(1) Clear Firefox's Cache

See: How to clear the Firefox cache

If you have a large hard drive, this might take a few minutes. If you do not see the number going down on the page, you can reload it using Command+r to check progress.

(2) Remove the site's cookies (save any pending work first). While viewing a page on the site, try either:

• right-click (on Mac Ctrl+click) a blank area of the page and choose View Page Info > Security > "View Cookies"
• (menu bar) Tools > Page Info > Security > "View Cookies"
• click the padlock or "i" icon in the address bar, then the ">" button, then More Information, and finally the "View Cookies" button

In the dialog that opens, live.com should be pre-filled in the search box at the top of the dialog so you can remove that site's cookies individually. If it isn't, change whatever is there to live.com so you can remove the right cookies.

Then try Hotmail again. Any improvement?

When I type those addresses I am redirected to a sign in page. It's after I sign in that my mailbox will not open all the way and fail to load. I cleared the cache already.

Just now i cleared the cookies and it worked. Let's see if it will work again tomorrow.

After 6 tries this a.m. it still fails to open! Other suggestions?

Does the current Firefox 50.1.0 release work, since you posted using a 51.0beta version?

Start Firefox in Safe Mode to check if one of the extensions ("3-bar" menu button or Tools -> Add-ons -> Extensions) or if hardware acceleration is causing the problem.

• Switch to the DEFAULT theme: "3-bar" menu button or Tools -> Add-ons -> Appearance
• Do NOT click the "Refresh Firefox" button on the Safe Mode start window

• https://support.mozilla.org/kb/Safe+Mode
• https://support.mozilla.org/kb/Troubleshooting+extensions+and+themes