GoogdI am far from an expert but you might try one of these easy experiences and/or bits of information so  we may help.

1)  What is the host OS (type and version if possible).

  2)  What are the guest OS's  again type or version)?

3)   Have you insttalled VMware Tools on either or both guests (instructions in the HELP section  but they "might" not be be complete  for Linux guestts  (prior thread)

4)   Does it matter whether or not you start M1 or M2 first?

5)   If the machine restarts does it boot up again?

6)   About how long does is the machine(s) running beforeethey reboot?

No doubothier moe edxpergt peo[ple people will have more than these simple questions to continue to help you.

At a certain point you might be asked to attach a vmlog but that might m ight not be necessay at this stage  in your case.

Good luck!!