I installed chrome and firefox on Oracle-Linux-7.4-2018.01.20-0 (ocid1.image.oc1.phx.aaaaaaaav4gjc4l232wx5g5drypbuiu375lemgdgnc7zg2wrdfmmtbtyrc5q). After connecting to the host using VNC, I cannot launch either of them. The mouse shows a firefox icon bouncing up and down for about 10 seconds. Then the icon disappears and nothing happen. Any idea? Thanks.