Hi,
The error message is telling you that frame number 17270 is corrupted. Usually it is a black frame, but it could also show as a white flash or artifacts. You need to expand your timeline and scroll to frame No. 17270 and surrounding area. Look for black frames, white flashes, or artifacts. Cut out any that you see. Now see if you can export.
You can find where frame No. 17270 is located by dividing the frame rate of your project into 17270. That will tell you the time point in seconds at which the frame appears. Multiply that by 60 to get the time point in minutes. So, for example, if your project is 30 frames per second divide 30 into 17270 to get 575.66 seconds as the point in the timeline where frame 17270 appears. Divide 575.66 by 60 to get 19.1 minutes as the point where frame 17270 appears. Scroll around in that area looking for black frames, white flashes, artifacts and anything else that indicates corruption.Cut out any that you see, and then try again to export.
If you want to preserve your original project, you can duplicate the project and work with the duplicate.
-- Rich