Steps to reproduce:

1. Create two triggers A and B
2. Make triggers in problem state
3. Convert A event to symptom of event B
4. Disable A trigger
5. Try to open symptom list of B cause

Result:

js error

Uncaught TypeError: Cannot read properties of undefined (reading 'classList')
    at Object.showSymptoms (zabbix.php?action=problem.view:230:16)
    at HTMLButtonElement.<anonymous> (zabbix.php?action=problem.view:194:13)

Expected:
Disabled trigger should not be considered. In this case, there should not be a list of symptoms