From several internet sites I learned that FF v55.0.1 is out for some days already. Normally I use the '?' -> 'About' way-of-working to get my FF updated, but currently I only see in the 'About' window that v54.0.1 (64 bits) is the one which is installed and there's a remark 'Firefox is up-to-date'. Like to know why the update functionality which normally works fine, is currently not able to detect the v55.0.1 for installment. I tried to add troubleshoot information as requested and clicked on 'Automatically add' (https://addons.mozilla.org/firefox/downloads/latest/troubleshooter/addon-426841-latest.xpi), but this revealed in a message like 'We're sorry, but we could not find what you where looking for'. So, I've 2 errors here. Adding manually the troubleshoot info was possible, however, see attachment