Cubase exports fast until 52% then it takes ages for each percent

Hey. I have a problem when i am exporting a file from a project in Cubase.
When it starts the export it takes 10 seconds until 52%, then after 52%, everytime, every percent takes like 5 minutes and Cubase jumps out from not responding to responding all the way to 100%. Some ideas?

No idea, but what happens when you do a realtime export?