Hello there,
I am experiencing the following issue. When I start Firefox 73.0.1-810.1 I am getting the following error:
XPCOMGlueLoad error for file /usr/lib64/firefox/libxul.so:
/usr/lib64/firefox/libnss3.so: version `NSS_3.47’ not found (required by /usr/lib64/firefox/libxul.so)
Couldn’t load XPCOM.
Does any one of you ran into the same issue?
Hi and welcome to the Forum 
How have you been updating your system, via command line and zypper dup?
Do you have any additional repositories enabled?
zypper lr -d
Your error shows mozilla-nss out of date (should be 3.49) and there should be no /usr/lib64/firefox/libnss3.so library, how was firefox installed?
zypper se -si mozilla-nss MozillaFirefox