Until this stuff is fixed for newer Firefox use this hack to get font size bigger:
create userChrome.css in the profiles /chrome folder and enter

@namespace url("http://www.mozilla.org/keymaster/gatekeeper/there.is.only.xul"); /* set default namespace to XUL */

menubar, menubutton, menulist, menu, menuitem, textbox,
toolbar, .tab-text, tree, tooltip, sidebarheader, statusbar {
font-size: 20px !important; }

THE NEW THEME AND FONT SIZE CHANGER IS TERRIBLE, I WANT THE OLD ONE BACK. IT IS CONFUSING AND THE
FONT CHANGER DOESN'T WORK. I USED TO BE ABLE TO HOVER OVER THE THEMES TO CHECK THEM OUT AND
THAT IS GONE AS WELL. WHY DO YOU HAVE TO KEEP CHANGING THINGS? YOU SHOULD HAVE LEFT WELL ENOUGH
ALONE. I WILL PROBABLY DUMP FIREFOX BECAUSE OF THIS.

Because of the limitations in customising Firefox 57 I will use Waterfox until it ceases to update. Why remove the functionality of this addon with the latest update? Please restore all functionality so that people who are happy using variations of Firefox which allow the old extensions can continue to enjoy your great addon, thank you :)

Wer kann mal auf deutsch erklären, wie man die sache wieder hinbekommt...habe auf hinzufügen geklickt, komme abertrotzdem nicht weiter....Danke!


Das war immer das Beste beim Mozilla Firefox...nun nicht mehr zu gebrauchen da ich die Schrift nicht mehr vergrößern kann...
Also wird die ganze Sache gelöscht....schade, oder wie bekomme ich die Sache wieder vergrößer?
Es handelt sich natürlich um Lesezeichen-Leiste....

Why tells us about something you no longer make available? It's stupid and irritating. Since your upgrade today the font size on my Bookmarks has become tiny. Why did you do this?

How the hell can I/we change the font size now on Bookmarks? Change to Chrome or Thunderbird?

It's the EASIEST to use, even for those not so Computer savvy, such as myself! Takes you through all the areas you would like to change!!!

Mit der Version 57 von FireFox hat Mozilla definitiv die rote Linie überschritten. Der "freie" Browser schreibt mir vor, was ich an Addons installieren darf? Geht gar nicht.

Nur dank dem Addon "Theme and Font Size Changer" konnte man FireFox überhaupt benutzen ohne Augenkrebs zu bekommen. Nun wird das verunmöglicht.

Das heisst für mich klar: Ich wechsle jetzt zu Google Chrome. Schade um die Idee des freien Browsers Mozilla!

Please Please bring this one to Firefox 57
My old eyes would be forever thanfull

If your add-on is no longer working, you'll need to downgrade to the previous version:
1- Remove (uninstall) the Theme Font& Size Changer addon
2- Go to this page and download/install version 56.0
https://addons.mozilla.org/en-US/firefox/addon/theme-font-size-changer/versions/
3- To prevent the add-on from updating itself to the latest version, you'll need to disable it (note: this will also disable auto-updates for all other add-ons). Follow these steps here: https://blog.mozilla.org/addons/how-to-turn-off-add-on-updates/

It is not working. The type is no longer larger & I do n ot see a way to make it happen.

I REALLY need this extension back! Please do all possible to hasten it's recovery. Thanks.

Can't find a replacement...if Firefox trying to get rid of all of us that need the larger fonts for the interface..all of a sudden it just disappeared...WAH! Firefox, we need this..please get it together...I'd hate to have to go elsewhere after all this time...old mac user

What happened to it??? The functionality is gone for fonts and size???

This is the only add-on / plugin for Firefox that makes it accessible for larger displays and old eyesight! :-)
Sure hope you can get it working with Firefox 57+, I know you are trying...
Thank you!

@ Nutzer 933ba4 Gehts noch etwas freundlicher! Auch wenn dieses Addon nicht mehr so ist wie es mal war, kann man sich
gut mit was anderem behelfen. Ich trauere jedenfalls nicht nach.

Spinnt ihr?
Seit Monaten verweigere ich Updates für Firefox, damit ich auf meine nützlichsten Addons nicht verzichten muss. Und jetzt bekomme ich von euch die lapidare Meldung, dass ihr eure Arbeit einstellt, weil Mozilla das so verlangt bei den neuen Versionen.
Gebt mir meine alte Version zurück!
Ich sch*** auf neue FF-Versionen, die werden sowieso immer schlechter, aber ich brauche dringend eure Erweiterung!

Was a great program but FF is determined to make the system font so small you can't read it, so this no longer works, due to the extensions support going away. FF is becoming all the things I hated about chrome. Hope at some point in the future this program will be useful again.