crash when exporting to interactive pdf from book

HI 

this seems a common problem. But so far I've not read any solution. Just many posts with people, like me, who are pulling their hair out.

I have a book with 190 pages. I can export half of them. And then the other half of them. What I can't do is export the lot. At page 190 indesign crashes.

I have deleted preferneces, re-installed, re-started the machine, recreated the book. 

I have 64gb of ram on a fast machine.

There are no bad links.

Anyone got any suggestions?

cheers