If the server MAC address changes, you will get an invalid license messages like the one you describe. Another thing to check is that perhaps license was originally binding to an interface different than eth0, in those cases, you need to pass the interface with the -i parameter to make the check, like:
/usr/local/fop2/fop2_server --test -i eth1
This is not needed any longer in recent FOP2 versions (from the last couple of years, not that recent), providing you have /etc/sysconfig/fop2 options configured with that parameter already (that you must if you want to startup the service with the correct licencs binding).
The "too many arguments" error also shows you have a kind of old/dated FOP2 version. My recommendation is to upgrade to the latest one.
Best regards,
