There could be many reasons. You may have a layer turned off in Construct 2 that shows up when you run. You may have initial visiblity set to invisible for the text or the layer it is on. You may change the font size or put in more text so that the text is too big for the text object, so it doesn't show up.
Without seeing your example or at least knowing what you are trying to do it is hard to know why you are having this problem.