VLC crashes on startup: Qt: Session management error: Could not open network socket

Question

I using Ubuntu 20.10. All of a sudden, VLC cannot be started. When trying to run it through the command line, I get:

$ vlc
VLC media player 3.0.12.1 Vetinari (revision 3.0.12.1-0-g170157402b)
[00005573fa81cb40] main libvlc: Running vlc with the default interface. Use 'cvlc' to use vlc without interface.
Qt: Session management error: Could not open network socket
Fontconfig warning: FcPattern object weight does not accept value [40 200)
Segmentation fault (core dumped)

Answer 1

This works for me:

sudo rm /var/cache/fontconfig/*
rm ~/.cache/fontconfig/*
fc-cache -r

Answer 2

VLC works well with the apt package, contrary to the snap package.

Answer 3

uninstall vlc first then install it again with

sudo apt-get install vlc -y
sudo apt-get update

Answer 4

I had a similar problem with Konqueror.

I ran pgrep konqueror (similar to ps -aux | grep konqueror) and killed the process (with kill, pkill or killall), then konqueror ran without issues.

Answer 5

This works for me:

before running vlc removes the network message. But it still does not start.

vlc -v

Answer 6

I had the same problem with another program. For me it was due to a restriction by the router: Ubuntu was connected to a FritzBox as guest and the FritzBox seems that was blocking this connection.

As soon as I changed to a normal connection, the problem was solved!