This error ( cannot write to IPC socket: broken pipe ) in Zabbix usually points to a communication breakdown between the Zabbix server (or proxy) and the Zabbix agent, or between Zabbix processes themselves. Here’s a to diagnose and fix it.
Summary
sudo systemctl stop zabbix-server zabbix-agent sudo rm -rf /tmp/zabbix_* # remove stale IPC artifacts (safe) sudo systemctl start zabbix-server zabbix-agent zabbix cannot write to ipc socket broken pipe upd