17.04fontsgnome-classic
I just updated Ubuntu to version 17.04.
When logging back after rebooting, GNOME seems to be behaving strangely:
Rogue top bar:
This strange "font" is used everywhere by the GNOME launcher:
Rogue launcher:
I've tried to reset the font using gnome-tweak-tool, but it doesn't change a thing.
How could this happen ? How can I set or reset the font ?
The older GNOME 2.x experience has been retired in GNOME, however you can use the GNOME 3.x classic mode (as shown below) to make an approximation of the older experience.
install prerequisites
In the software center you have the option to install Gnome Shell :
Similarly - search for CompizConfig Settings Manager and install this package - we'll need that later.
Whilst you are there you can also install gnome-tweak-tool to further customise your desktop.
To quickly install all three of these at once, copy and paste the following into a terminal:
sudo apt-get install gnome-shell compizconfig-settings-manager gnome-tweak-tool
enabling compiz
Now perhaps the tricky part - getting gnome classic to function with compiz:
In a terminal copy and paste the following:
gksudo gedit /usr/share/gnome-session/sessions/gnome-classic.session
Now edit the file shown to contain this line entry:
How to login to Gnome-Classic
Save, logout and in your session options choose Gnome Classic
Changing the theme
You'll notice that the default Ubuntu Ambiance theme doesn't look great in Gnome Classic. We can correct this by changing to a Gnome 3 friendly theme.
... and choosing Appearance 
Change the theme to Adwaita...
Note - see the linked questions below for other theming options.
Changing Icons
Launch gnome-tweak-tool via the menu option:
Change the icon theme as shown:
Restructure the desktop layout
Now lets get back the panels to something that we are familiar with...
Press Alt+Win and right-click the top menu bar - N.B. Win is the Windows Symbol key
(If you are using Gnome Classic (No Effects) i.e. gnome fallback mode then to add to the panel use Alt and right-click)
Choose Add to Panel
Click the option shown and click the button Forward
Repeat the Alt+Win + Right Click the date and choose Delete to delete the clock.
Repeat this delete procedure for the other applets on the top-panel.
Note - if an error appears indicating that the Panel has reloaded you can safely ignore this.
Repeat the Alt+Win + Right Click the top panel - add the applet Accessibility.
Repeat the Alt+Win + Right Click on bottom panel - add the applet Show Desktop and move to the bottom left.
Repeat the Alt+Win + Right Click on bottom panel - add the applet Wastebasket and move to the bottom right.
Now we need to change the number of workspaces back to two.
Navigate to Applications - Other - CompizConfig Settings Manager - General Options - Desktop Size and change the Vertical Virtual Size value to 1
Install the indicator-applet
Now lets install the indicator-applet:
To add to the panel:
Alt+Win+Right click the panel and choose Add To Panel and add the following indicator
Finish off by Alt+Win+Right click the indicator-applet and move it to the right side of the top panel.
Optional:
Linked Questions:
I presume evince is looking like this:
I would use XFCE packages to help you on this issue:
sudo apt-get install xfce4-settings
Then run the xfce daemon:
xfsettingsd
This will change the fonts to use GTK settings.
Run xfce4-settings-manager to change your fonts and icons:
Obviously you would want to run the daemon from login - see my linked answer on how to do this.
Linked Question:
Best Answer
I had the same issue.
My solution was like so:
And all fonts appear.