Last Modified: Feb 03, 2026
Affected Product(s):
BIG-IP LTM
Fixed In:
21.0.0.1
Opened: Nov 17, 2025 Severity: 3-Major
Continuous restart of MCPD accompanied by error messages: An unexpected failure has occurred, MCO_ERR_EV_SYN - Synchronous events.
BIGIP services are impacted as MCPD is down.
This occurs after 10 restarts of MCPD service.
Reboot device.
This issue is fixed by cleaning up the resource during every MCPD restart.