Here are your choices; 1) Contact its support and ask if they will update 2) Find a replacement 3) Downgrade to a prior Firefox 4) Do without

First, Type about:preferences#advanced<enter> in the address bar. Under Advanced, Select Update.

[v57+] Type about:preferences#general<enter> in the address bar. Select Update.

Check the settings.

Also turn off Use a background service to install updates

Install Older Version Of Firefox {web link} Be sure to read everything here.

If you still want to downgrade, look under; I still want to downgrade. Click the Directory of other versions and languages link. Look for the directory of the version that you want. But, remember that old versions may have security issues.

You should also check out Firefox; Extended Support Release {web link} ESR Notes System Requirements

Your answer of checking for updates is not relevant. As I mentioned it WAS the latest update that caused the problem. I have the latest version. Reverting to an older unsupported version, which may have "security issues" so I can still use FireFTP is also not a very satisfactory answer. I have been a touting for years that Firefox is the best standards compliant browser to MANY customers I work with but this update has really changed my view. I guess I am going to go with the recommendation of the creator of FireFTP and switch to WaterFOX browser.

Expanded from above : Going back : unfortunately 56.0.2 is no longer safe to use for every day use, but 52.5.0 ESR is! It will continue to get security updates until May 2018, and you can download and install it from this page: https://www.mozilla.org/en-US/firefox/organizations/all/ Note : Legacy Extensions will be deleted or removed in any version update after May 2018. You should make a backup of your Profile before going back and just because: https://support.mozilla.org/en-US/kb/back-and-restore-information-firefox-profiles

There is usually a file in any FTP client that holds your info. Is a matter of finding the file and then find what can view the contents with. Search for the Folders for this. It should be obvious as to the file once find it. If not go to their support page, with luck there should be something on it for backing up those files and the file should be named. If not Contact them.

Reasons : https://support.mozilla.org/en-US/questions/1187457 How about looking at these 2 URL's first : https://www.howtogeek.com/333110/how-to-customize-firefox-quantum-and-remove-the-white-space-around-the-title-bar/ and The name is not descriptive enough : https://www.howtogeek.com/332449/whats-new-in-firefox-quantum/

More information will come out slowly. New extensions are being made and some older ones being updated that are tracked here : http://bit.ly/2j0Anlj

As for moving browsers that is completely up to you. Enjoy your Firefox based Waterfox.

Please let us know if this solved your issue or if need further assistance.