I asked a question before and got an answer.
Error no outout, but it does not appear in the preview.
I don't know the cause.
I'm at a loss....
"Enable but do not run", "Enable (waiting for approval)" Can Ipreview in this state? Can preview without sending?
Am I doing something wrong?
instance.vars.yearTest = formatDate (new Date(), "%Y")
delivery.variables._var  .stringValue = instance.vars.yearTest
Text Content Tab
Everything you have there is correct (though it can be reduced to <%= formatDate(new Date(), "%Y") %> ;).
You can preview 'without' sending by sending the delivery with confirmation/approvals enabled.
Once sent, the executed delivery can be opened and previewed against target population/vars before confirm button is pressed.