Regarding media durations and how it’s affecting the layout playback please have a read here:
Now regarding:
It means that there was a fatal error during upload.
Could you please go to Report Fault page in your CMS (check if everything there is ticked or if you have any positions) then → turn on debugging → reproduce your issue (try to upload something) → save log file → send it to us (upload created .txt to dropbox or similar and give us a link here)