What does having * * * mean in the command traceroute ? and How can you cope with that situation?

It means that the affected host (in your example, the second one) did not reply to the traceroute. As by default traceroute uses an UDP port, you can change the discovery protocol to use ICMP/PING using the "-I" option. Apart that, you can not do anything more.

It means that a packet with a tweaked TTL did not return an appropriate ICMP TTL exceeded packet, or that those packets were lost on the way back, within the given period traceroute waits for them. This CAN mean, that the host on the way is not generating them properly, if at all.

There is little you can do about this. You can change the protocol traceroute uses for its discovery (as described by shodanshok), or increase the timeout (traceroute -w 15 for example). Also try to reduce the number of requests sent (-N 5).

P.S. You can also try to use some tool to utilise RECORD_ROUTE for example hping3. But I cannot give you any more details as I have never been able to use it.