I am a musician and keep my fake books - large PDF files - on Dropbox. There are several of them and they're about 25-30 MB apiece. All open OK on my MacBook, iMac and Android devices, and all but one of them open OK on my (iOS 10) iPad.
The one that won't open on the iPad locks up the app to the point that I have to force quit it. This happens immediately when I click on it - no progress bar or anything.
I re-saved an "optimized" version which reduced the size about 25%. and I took out all the color pages and saved a monochrome version - the changed versions show a loading progress bar but after that they revert to the original behavior - lockup as soon as I click on the file. Any suggestions?