I don't understand why you are using Shift, and I don't know if ClickButton accepts any parameters.
This is the reason I'm not able to provide a proper solution, because it's confusing!
I'm not using a Shift, it's by default. I just showed here that TC uses key as a value, maybe it accepts only key as value for this operation.
I was using a variable and when I was using a variable it didn't work because of Exception - Type mismatch.
Maybe this is a reason why it says "Type mismatch." because variable is a different type.
I can't find any information. I created TC support ticket yesterday about this, but didn't get a respond yet.
