Acrobat DC freezes when inserting png and jpeg images

Hi, I'm a brand new Acrobat user and I'm attempting to add new images to a document.

When inserting .png or .jpeg files after either the second, third or sometimes the fourth image insertion, Adobe Acrobat DC then freezes. I cannot do anything other than force quit and relaunch the application.

It's very frustrating because I'm working to a deadline!

Chat support have no idea and I'm now expecting a call from their 2nd level tech support team within the next 72hrs.

I am using a Mac running El Capitan 10.11.6. This is the latest update and Acrobat is also up to date.

Please help if you can!