Well still a problem - now 100% of the time!! - and seems to be affecting quite a few people. Does anyone have any ideas? Are Mozilla or Microsoft even aware of this? There seem to have been quite a few other issues with Firefox and Hotmail of late! Thanks

This issue can be caused by corrupted cookies.

Clear the cache and the cookies from sites that cause problems.

"Clear the Cache":

• Tools > Options > Advanced > Network > Offline Storage (Cache): "Clear Now"

"Remove Cookies" from sites causing problems:

• Tools > Options > Privacy > Cookies: "Show Cookies"

As I said we "tried the Firefox cookies/cache clearing trick".

If we clear the cookies and cache before signing in to Hotmail then we can write or reply to one email (!). All subsequent attempts to write or reply to emails in that session are met with the "Bad Request" response. So it may well be cookie-related but in that Microsoft are sending corrupted or non-Firefox compatible cookies mid-session!

If you clear the cookies/cache mid-session then you are automatcally logged out of Hotmail and must begin the cycle again.

Any other ideas?!!! Anyone?!!!

If clearing the cookies doesn't help then it is possible that the file cookies.sqlite that stores the cookies is corrupted.

Rename (or delete) cookies.sqlite (cookies.sqlite.old) and delete cookies.sqlite-journal and cookies.txt, if they exist, in the Firefox Profile Folder in case the file cookies.sqlite got corrupted.

• http://kb.mozillazine.org/Profile_folder_-_Firefox

You can also try if it works if you switch to Private Browsing mode.
That gives you a new set of cookies.

Thanks. Tried the above - Renamed cookies.sqlite (cookies.sqlite.old). No instance of either cookies.sqlite-journal or cookies.txt in profile folder. Launched Firefox (confirmed new cookies.sqlite created in profile folder as well as cookies.sqlite-journal) and logged into Hotmail. First attempt at replying to an email resulted in the dreaded "Bad request". Tried Private Browsing. New cookies created so was able to reply to one email but subsequent attempts were, you guessed it, "Bad request" Any further suggestions welcome.

I am also having same problems. Clear cookies etc and manage to send 1 e-mail then Bad Request etc! Never had this problem before....is it linked to latest firefox update that also caued me problems with add ons etc......Hopefully a fix/solution will be found and advised sooner rather than later......

Hi all (Courtney66's other half here!).

After much 'research' (i.e. fiddling with stuff) we think we have found a solution albeit, hopefully, a temporary one that works for us (until MS sort it out!!).

Log in to Hotmail using https (Secure protocol) rather than plain old http. Just add an 's' after the 'http' part in the address bar of hotmail, e.g. https://hotmail.com or https://mail.live.com.

You can even do this mid-session i.e. while you're already logged in to Hotmail. You should be prompted to continue using https just for that session or to make the setting permanent and there may be a subsequent caveat regarding Outlook Hotmail Connector and Windows Live Mail but I believe MS have addressed these issues in the last few weeks so you need to make sure both have the latest updates if you use either of those. http://windowsteamblog.com/windows_live/b/windowslive/archive/2011/07/06/coming-this-week-an-update-to-windows-live-essentials-2011.aspx .

There's also an option to "Use HTTPS automatically" in your Account settings to make this permanent. http://explore.live.com/windows-live-hotmail-https-using .

When logging in with https we are now able to reply to and write emails in Firefox.

Hope this helps!!

This is a new problem for me too. When I click on Tools I do not have "Options". Any other suggestions?

Are you on a Mac or on Linux?

• http://kb.mozillazine.org/Menu_differences
• Windows: Firefox (Tools) > Options
• Mac: Firefox > Preferences
• Linux: Edit > Preferences

The sollution is indead the Https you have to change when you log in with firefox.