Problems with export to PDF

Hi,

I'm using Photoshop Elements 2018 on an iMac. I've did a photobook (size 1.4GB, 28 Pages, appr. 40 pictures) and want to export it to pdf. Since today photoshop elements shut down after a few seconds. The pse file of the photobook isn't damaged , I can restart photoshop elements with out problems. I had restart my iMac sevral times I had clean cache, I had increased working storage. If export a file with 150 MB to 250 Mb to pdf I don't have any problems. Any idea except creating smaller sized photobooks how to fix the problem?

Thanks for your help

Michael