Easy URL to test: https://self-signed.badssl.com/
There are two ways:
toggle Firefox to set server certificates added as Lifetime Permanent by default
in about:config toggle security.certerrors.permanentOverride to true
add the exception as usual (as described by OP), it will have the Lifetime property set as Permanent
reference from mozilla ticket ...
Sorry if you actually tried the obvious one but have you set Firefox as your default browser in Preferred Application settings?
For me Firefox is set to default in Preferred Applications AND in Firefox.
From this Reddit post, we found that the bspwm's focus_follows_pointer option causes the screens to appear as windows in sharing menus when it is set to true.
Those screens should not even appear in the first place. According to this comment by /u/ortango_, sharing them isn't even supposed to work:
Firefox does not support sharing per monitor. those things ...
The Firefox profile manager found an issue with my Firefox profile and loaded the default factory settings. If you encounter similar issues, make sure you have loaded the expected profile.
Note you can start the Firefox profile manager from terminal with
$ firefox --ProfileManager
There is no way to force a GTK app to reload the DPI built in to the framework itself. However, contrary to the comment you received, many GTK apps subscribe to the GSignal notify::gtk-xft-dpi on their GtkSettings instance.
If you use gnome, when you are in gnome-control-centre and you update the DPI, or you plug in a monitor, in the background gnome will ...
I finally found the solution!
Running /usr/lib/x86_64-linux-gnu/gdk-pixbuf-2.0/gdk-pixbuf-query-loaders --update-cache made the icon reappear.
After various attempts of uselessly removing and reinstalling Firefox, I observed that it was crashing when trying to drag tabs, with the following message:
(crashreporter:11662): Gtk-WARNING **:...
The Java Plugin was removed in Java 8 Update 271.
From the Java 8 Update 271 (8u271) release notes:
Removed Feature: Java Plugin is Removed from JDK 8u for Linux, Solaris, and MacOS Platforms
NPAPI is considered to be a vulnerable plugin and has been disabled in many browsers. No browsers currently support Java Plugin, which is NPAPI-based, on Linux, ...