Comment 16 for bug 1845362

Same problem on Ubuntu 21.04. started gnome-font-viewer from terminal the window opens but is unresponsive. closing it I have the crash and a message:
corrado@corrado-n8-hh-0101:~$ gnome-font-viewer

(gnome-font-viewer:4532): Gdk-ERROR **: 08:22:36.317: The program 'gnome-font-viewer' received an X Window System error.
This probably reflects a bug in the program.
The error was 'BadIDChoice (invalid resource ID chosen for this connection)'.
  (Details: serial 1502 error_code 14 request_code 130 (MIT-SHM) minor_code 5)
  (Note to programmers: normally, X errors are reported asynchronously;
   that is, you will receive the error a while after causing it.
   To debug your program, run it with the GDK_SYNCHRONIZE environment
   variable to change this behavior. You can then get a meaningful
   backtrace from your debugger if you break on the gdk_x_error() function.)
Trace/breakpoint trap (core dumped)
corrado@corrado-n8-hh-0101:~$

corrado@corrado-n8-hh-0101:~$ apt policy gnome-font-viewer
gnome-font-viewer:
  Installed: 3.34.0-2
  Candidate: 3.34.0-2
  Version table:
 *** 3.34.0-2 500
        500 http://archive.ubuntu.com/ubuntu hirsute/main amd64 Packages
        100 /var/lib/dpkg/status
corrado@corrado-n8-hh-0101:~$ inxi -SCGx
System: Host: corrado-n8-hh-0101 Kernel: 5.8.0-25-generic x86_64 bits: 64 compiler: gcc v: 10.2.0
           Desktop: GNOME 3.38.2 Distro: Ubuntu 21.04 (Hirsute Hippo)
CPU: Info: Quad Core model: Intel Core i5-1035G1 bits: 64 type: MT MCP arch: Ice Lake rev: 5
           L2 cache: 6 MiB
           flags: avx avx2 lm nx pae sse sse2 sse3 sse4_1 sse4_2 ssse3 vmx bogomips: 19046
           Speed: 813 MHz min/max: 400/1000 MHz Core speeds (MHz): 1: 813 2: 998 3: 989 4: 997 5: 966
           6: 980 7: 954 8: 974
Graphics: Device-1: Intel Iris Plus Graphics G1 vendor: Dell driver: i915 v: kernel bus ID: 00:02.0
           Device-2: Realtek Integrated_Webcam_HD type: USB driver: uvcvideo bus ID: 1-6:3
           Display: x11 server: X.Org 1.20.9 driver: modesetting unloaded: fbdev,vesa
           resolution: 1920x1080~60Hz
           OpenGL: renderer: Mesa Intel UHD Graphics (ICL GT1) v: 4.6 Mesa 20.2.6 direct render: Yes
corrado@corrado-n8-hh-0101:~$