Well I have been having this problem, and I have no idea how to fix it. When you select the trigger Unit -Remove, and go to select a unit then usually it just puts that unit in the variable, but it won't let me do that, is there any fixing that?
That trigger requires you to select a premade unit, so that specific unit would be manipulated for your trigger.
I would make a trigger to help you with your problem, but I dont have that kind of time tonight.
There should be a boolean? condition or maybe even some sort of action that involves only that type of unit. So instead of using a premade, such as Medivh 0274, you can find the correct trigger that manipulates any Medivh unit.
yes, you need to provide us with more information of what you want your trigger to accomplish, and it wont automatically create unit variables, unless you have previously hit "Select Unit" or have created a variable in the variable editor