Executing custom command as action operation produce "write: Broken pipe" error in server logs.
1. Configure simple Host, Item and Trigger
2. Go to Configuration->Action->Create Action
3. Name action in "Action" tab
4. Add your trigger in "Conditions" tab (see possible variant on 01_Conditions.jpg attached)
5. Configure operation to run simple custom command with output into standard output and run it on server side (not agent). For example simple "date" call. (see possible variant on 02_Operation.jpg attached)
6. Make action to run
7. Observe "write:Broken pipe" error message in zabbix_server log file