restart the service with the service conected via ssh:
service fop2 restart
If it doesn't work for you, the license may be wrong. You have to remove it and reinstall it with the following commands connected to the internet:
/usr/local/fop2/fop2_server --revoke --rp=http
put your license code
/usr/local/fop2/fop2_server --register --rp=http
put your license code again
