"Starting in Firefox 47, the Fonts view is disabled by default. We're working on a more fully-featured replacement." https://developer.mozilla.org/docs/Tools/Page_Inspector/How_to/View_fonts.
To restore the old panel that we've often told users to check when they encounter problems with downloadable fonts or simply bad-looking fonts:
(1) In a new tab, type or paste about:config in the address bar and press Enter/Return. Click the button promising to be careful.
(2) In the search box above the list, type or paste devt and pause while the list is filtered
(3) Double-click the devtools.fontinspector.enabled preference to switch it from false to true
"Starting in Firefox 47, the Fonts view is disabled by default. We're working on a more fully-featured replacement." ''[https://developer.mozilla.org/docs/Tools/Page_Inspector/How_to/View_fonts https://developer.mozilla.org/docs/Tools/Page_Inspector/How_to/View_fonts]''.
To restore the old panel that we've often told users to check when they encounter problems with downloadable fonts or simply bad-looking fonts:
(1) In a new tab, type or paste '''about:config''' in the address bar and press Enter/Return. Click the button promising to be careful.
(2) In the search box above the list, type or paste '''devt''' and pause while the list is filtered
(3) Double-click the '''devtools.fontinspector.enabled''' preference to switch it from false to true