Hi,
Without knowing your topology, location of multicast source and what PIM mode is configured, it's difficult to give a precise solution. However, issues could be due to the default CoPP (Control Policing) or the Multicast table size.
I would suggest the following:
1. Disable the CoPP rate-limit with the config mode command copp rate-limit disable. If this works, then you may have to renable CoPP with no copp rate-limit disable, and adjust your CoPP policing. Disabling CoPP may lead to overwhelming your Supervisor.
2. You may instead choose to increase the Multicast table with the command hardware profile multicast max-limit size. Maybe try a size of 5000 or 6000, if you have heavy multicast traffic and fewer unicast entries.