First, before giving you "the usual," do you know whether you are using a beta test version of Outlook.com? There may be a button to change back to the regular version in that case.

If a site is generally known to work in Firefox, these are general suggestions to try when it stops working:

Cache and Cookies: 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, the current site should be pre-filled in the search box at the top of the dialog (probably live.com) so you can remove that site's cookies individually.

Then try reloading the page. Does that help?

Testing in Firefox's Safe Mode: In Safe Mode, Firefox temporarily deactivates extensions, hardware acceleration, and some other advanced features to help you assess whether these are causing the problem.

If Firefox is not running: Sorry, this was for Windows: Hold down the Shift key when starting Firefox. Hold down the option/alt key when starting Firefox.

If Firefox is running: You can restart Firefox in Safe Mode using either:

• "3-bar" menu button > "?" button > Restart with Add-ons Disabled
• Help menu > Restart with Add-ons Disabled

and OK the restart.

Both scenarios: A small dialog should appear. Click "Start in Safe Mode" (not Refresh).

Any improvement?

It works in Beta but I would rather not use that. When I open emails, the contacts are not recognized so I can't reply - the same with new emails. Outlook in Safari wasn't working either, then it started to work, now again the email address of sender doesn't appear and can't be replied to. Also not working in Safari on my phone.

Now is it working without my doing anything. Is it a general Outlook problem??

adele565 said

Now is it working without my doing anything. Is it a general Outlook problem??

That's hard to answer... Certainly complex websites sometimes have problems that get fixed without any notification to their users.