I recently deleted a host group that was part of an trigger actions custom condition.

The action was automatically disabled which is what I would expect.

However I was able to enable the action without modification just by clicking the enable/disable toggle shortcut in the action list page.

This causes an issue as the Action to be enabled that currently has an incorrect custom expression due to the deleted host group, where by the conditions seem to get evaluated and as a result lots of triggers were processed through this action.

If you dont use the enable/disable shortcuts and infact open the action then try to update the enable/disable state it does in fact produce an error relating to the incorrect custom expression.

Should the enable/disable shortcuts also produce an error in this case as well?

Steps to reproduce:

1. Create host groups H1, H2, H3
2. Create action with host groups H1, H2, H3 as conditions with a 'custom expression' 'A and B and C'; Add an action to do anything.
3. Delete host group H2 and you will see the action is disabled
4. Enable the action using the shortcut and not by updating the action

Result:

The action will now be enabled with an incorrect custom expression causing unexpected action/trigger evaluation.

In our case a team received unexpected emails/incidents from another teams monitored hosts.

Expected:
When enabling the trigger via the enabled/disable toggle shortcuts with an incorrect custom expression it should produce an error and prevent the action status change.