cant export my slideshow to a movie

[tomtomlev]

HI
I'm using Windows 8 + PowerPoint 2013



I have a slideshow that I created in PP 2013
(I admit it's large and has a lot of media in it)

when I'm trying to export it to a movie all of a sudden after a random time of the process I get an error message:
PowerPoint could not finish creating video <Filename.mp4>. Do you want to try again?

of course trying again causes the same message to appear.
I tried to delete some stuff from the slideshow, restart, delete temp files... nothing helped
I tried to cut the presentation to 2 (it's 150 slides total) and then export each half separately. it helped for 1 half but it's a neverending job!

isn't there a logfile? event? something I can use to help debug it?!
this error message is sooo general and so unhelpful!

would love to hear some ideas!