This causes an error message, which is good.
run,,, UseErrorLevel if ErrorLevel msgbox error else msgbox ok
This doesn't cause an error message but sets the ErrorLevel, which is also good.
var := "asd" run, % var,, UseErrorLevel if ErrorLevel msgbox error else msgbox ok
However, this does not set the ErrorLevel, that I think it should.
var := "" run, % var,, UseErrorLevel if ErrorLevel msgbox error else msgbox ok
