Or, to follow John's post, that the text seems to "disappear" because the selected colour doesn't show against the black background? If that's the case you need to change that background colour. Though I'm pretty certain in the most recent versions it changes automatically (or am I imagining that?)
Whatever, as John pointed out, we need much more information about your system etc. as per the post he pointed you to.
Can't remember whether MEP 14 allows you to change the background colour for text objects but, in any event, the text doesn't disappear (as in vanishes) but is simply "invisible". In other words it's still there and if you click to insert it to the movie, the background will disappear to reveal the actual words.