looks like a pulse audio issue
do you have pulseaudio installed?
you can try using pavucontrol to setup pulse audio
you can also use the hardware section in yast to setup (and enable pulse audio)
to install pavucontrol (which should install pulseaudio too) do
that doesn’t give us much info we don’t know from where gstreamer is (in your case it doesn’t matter)
I have installed (latter removed) viber on LEAP aside from linking the 64bit shared object libcrypto.so.1.0.0 to libcrypto.so.10 there is nothing else to be done
what I did to get viber working on a clean system
ln -s /usr/lib64/libcrypto.so.1.0.0 /usr/lib64/libcrypto.so.10
ldconfig
zypper in /path/to/viber.rpm
that being said I’ve never used xfce afaik it should use pulseaudio unless you chose an exotic install
/opt/viber/Viber
Qt WebEngine ICU data not found at /opt/viber/resources. Trying parent directory...
Qt WebEngine resources not found at /opt/viber/resources. Trying parent directory...
Qt WebEngine ICU data not found at /opt/viber/resources. Trying parent directory...
Qt WebEngine resources not found at /opt/viber/resources. Trying parent directory...
PulseAudioService: pa_context_connect() failed
PulseAudioService: pa_context_connect() failed
Assertion 'pthread_mutex_unlock(&m->mutex) == 0' failed at pulsecore/mutex-posix.c:108, function pa_mutex_unlock(). Aborting.
Аварийный останов (core dumped)