Make sure that you allow cookies for the accounts.firefox.com domain if you aren't allowing cookies generally or use the 'Ask me' cookie setting.

To see all History and Cookie settings, choose:

• Tools > Options > Privacy > Firefox will: "Use custom settings for history"

• https://support.mozilla.org/kb/Options+window+-+Privacy+panel

You can inspect and manage permissions for the domain in the currently selected tab via these steps:

• Click the "Site Identity Button" (globe/padlock) on the location/address bar
• Click "More Information" to open "Tools > Page Info" with the Security tab selected
• Go to the Permissions tab (Tools > Page Info > Permissions) to check the permissions for the domain in the currently selected tab

Im sorry this doesnt work. I have done the first part which was as it was. I do not understand what I am suppose to be checking on the second part under security.. I still cannot log in to Sync

A few things that you can try: Disconnect Sync and reconnect to Sync. Delete the signedInUser.json file in the profile folder with Firefox closed and possibly delete the Weave folder as well. Delete and re-create the FxA account.

• https://accounts.firefox.com/settings

You can use this button to go to the currently used Firefox profile folder:

• Help > Troubleshooting Information > Profile Directory: Show Folder (Linux: Open Directory; Mac: Show in Finder)
• http://kb.mozillazine.org/Profile_folder_-_Firefox

I can log in and out. I cannot do any of these other things. The Sync arrows are constantly turning and when I click on it I am taken to a blank page. This is just not working. i cannot disconnect from Sync as I cant open it.

Update: I have refreshed firefox and now the Sync arrows are not turning anymore but when I click on sign into sync I still get a blank page with the address about:accounts?entryPoint=menupanel.

There has to be a fix for this. 6 months ago it was working!

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

• Rename (or delete) cookies.sqlite (cookies.sqlite.old) and delete other present cookies files like cookies.sqlite-journal in the Firefox profile folder in case the file cookies.sqlite got corrupted.

You can use this button to go to the currently used Firefox profile folder:

• Help > Troubleshooting Information > Profile Directory: Show Folder (Linux: Open Directory; Mac: Show in Finder)
• http://kb.mozillazine.org/Profile_folder_-_Firefox

Create a new profile as a test to check if your current profile is causing the problem.

See "Creating a profile":

• https://support.mozilla.org/kb/profile-manager-create-and-remove-firefox-profiles
• http://kb.mozillazine.org/Standard_diagnostic_-_Firefox#Profile_issues

If the new profile works then you can transfer files from a previously used profile to the new profile, but be cautious not to copy corrupted files to avoid carrying over problems.

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

I cannot follow these steps. Where do i find the cookies? I also do not find the profile manager/folder or directory.

Could you pleasse give me excat step by step instructions as to do these things.

See these for some information about cookies:

• http://kb.mozillazine.org/Cookies
• https://support.mozilla.org/kb/Cookies
• https://support.mozilla.org/kb/Deleting+cookies

Did you open the troubleshooting information page? That page has a button to open the Firefox profile folder.

• https://support.mozilla.org/kb/profiles-where-firefox-stores-user-data
• https://support.mozilla.org/kb/Using+the+Troubleshooting+Information+page

So I have managed to delete the cookies. I managed to create a new account as well. When I try to sync with the new account I get the sync page. Obviously my old account is corrupt somehow. So how do I figure out what is wrong when I am logged into my old account? All my bookmarks, open tabs etc are in the old account so I will need them. In the new account is nothing, obviously as it is new. First step achieved thank you. Please could you help me to the next step. Thank you for your time and patience.

You can try to change the password of the old Sync account. That should reset all data stored on it.

Did you manage to perform these steps that I posted above?

Delete the signedInUser.json file in the profile folder with Firefox closed and possibly delete the Weave folder as well.

• Help > Troubleshooting Information > Profile Directory: Show Folder (Linux: Open Directory; Mac: Show in Finder)

I did try the steps above. I cannot change the password of the sync account as when I try to sign in I get a blank page.

Will deleting the signedInUser.json file in the profile folder delete all my bookmarks, settings, open tabs etc?

Could someone please help me with this problem? Somebody has to know the answer. I cant be the only one!