I didn't realise how much I used the task bar on Firefox - or more specifically, the hover-over links function which shows the link destination on the task bar.

When Firefox went for the grotty "Australis" layout, this useful feature vanished. As far as I know, one needs the Status-4-Evar add-on to bring it back.

The update to Firefox 55 broke this useful function.

However, an update to Status-4-Evar has brought things back to normal for me today. I see NoScript has also been updated - although that happens a lot, anyway - a very switched on developer.

With all the legacy add-ons (virtually all of them - Ghostery is an exception) scheduled for execution with Firefox 57 (I think), there might be merit in disabling auto-updating for Firefox until suitable updates/replacements for all one's favourite add-ons are available. This applies especially if, like me, you find all the available and high quality add-ons are what really "make" Firefox.

Another option is to use the extended support version of Firefox, which should last about half way into next year, IIRC.