Pages not working after upgrade to 4.5

All my portfolio pages have stopped working since the upgrade to 4.5 and I have no idea how to get them back. Can anyone advise?

My site is https://www.naturenurturephotography.com and was built using the divi theme from Elegant Themes. I didn’t build it myself, and although I can update the parts of the site I need to I have absolutely no idea how to fix this.

Thanks