Symptom:
Modules may experience l2mcast process crashes:

2-SERVICE_CRASHED: Service "l2mcast" (PID 1220) hasn't caught signal 11 (core will be saved).

A process crash may occur multiple times over multiple modules

Conditions:
The issue was first seen with v2 joins (*,G)  and v3 joins (S,G) and has OMF disabled on the fabric path vlan 182.  We see a  bunch of leaves coming in for the (*,G)s on vlan 182. Since there are v3 joins as well , some of the  (*,G)s have corresponding (S,G) s.  Ideally , if a  (*,G) delete comes in we wouldn't be deleting the  (*,G) from our software db if we have an (S,G) entry for the same group and that (S,G)  delete is yet to come . Only when all the (S,G) leaves comes in and number of  Source specific entries for that Group becomes zero ,  we cleanup the (*,G) entry node in our software. Once all the Groups in a Vlan are cleaned up , we will go ahead and clean up the Vlan entry in our sw db.  To be able to do so in a correct manner we keep count of number of G entries per  Vlan per ftag and number of S entries per G etc.  {  note :  S is short for Source , and G is multicast group address}