Which file? That error page?
Can we step back a little and make sure we are talking about the same thing here.
When do you get the message seen in the screenshot? Are you using EW from a browser and click the Download button?
If so, are you getting that right away, or do you get an RBZ downloaded?
Have you tried using the Extension Store from within SketchUp to install TT_Lib?
Also, what SketchUp version and what OS?