Use the lower dropdown and set it to "is blank". Rather than equal to nothing like how you have it.
I would add the rule conditions you have above toe the status field, and then have the action be a message or whatever to alert the user that the resolution field is blank.
The other way to do it is add a rule to status that is resolution isblank then set ti to readonly. That way they cannot change status until there is a value in resolution.
