Actually the file is damaged. Happens quite often with Prime and Prime does not provide any means for automatic backups or for repairing damaged files.
Hope you can fall back to a recent backup.
EDIT: I was able to recover part of the file, but while most embedded pictures still were there, the Prime file had lost the references. For whatever it may be worth I attach the Prime file (without the pictures) and pictures themselves in the zip file "media".
Maybe someone else is able to do a better job in repairing the file.
