Symptom:
EPMC process crashed producing one or more core files.
Leaf # show system reset-reason 
*************** module reset reason (1) *************
0) At 2015-12-13T07:14:07.845+11:00
Reason: reset-requested-due-to-fatal-module-error
Service:Service on linecard had a hap-reset
Version: 11.1(3f)

admin@apic:~> show cores
troubleshooting:
node  module  creation-time          file-size  service-name  process  original-location                      exit-code           death-reason       last-heartbeat
----  ------  ---------------------  ---------  ------------  -------  -------------------------------------  ------------------  -----------------  --------------
102   1       2015-12-               0          epmc          5258     /var/sysmgr/logs/                      describe-the-const  check-return-code  0.000000
              17T23:03:18.000+00:00                                    1450393398_0x102_epmc_log.5258.tar.gz
102   1       2015-12-               31356727   epmc          5258     /var/sysmgr/logs/                      6                   2                  7.000000
              17T23:03:19.000+00:00                                    1450393399_0x102_epmc_log.5258.tar.gz
102   1       2015-12-               21989231   epmc          5395     /var/sysmgr/logs/                      6                   2                  4.780000
              17T23:07:09.000+00:00                                    1450393629_0x102_epmc_log.5395.tar.gz

Conditions:
Occurs when one or more endpoints are rapidly moving between a FEX port and Leaf port, usually caused by a loop in the environment.