Confirm with your network admin if you're using IPSec/UDP.
The license software does not support NAT
Check with your network admin if you’re using VPN – If you are using VPN, and packets aren't being lost, you may need to decrease the MTU size to 1300, or less (1500 is generally the default). The reason for this is that sometimes extra security header information can be added to the packet (1314 bytes from client, 1474 bytes from server), and if the MTU size is exceeded in this way, it likely won't work. Decreasing the MTU size to force packet fragmentation at a lower packet size seems to fix this. For this you should consult with your network administrators on how to change these settings appropriately.
If other utility such as commuter licenses, and WLMAdmin, work, but QTP does not, this is also
We are getting the error from when we try to connect via VPN from a machine that is geographycally in a different continent. We tried reducing the MTU size on the firewall and it still does not resolve the license error. Should we reduce it on the License Server too?