I, too, am having this error message. I read somewhere that it is either because of the font Helvetica Nueue, or because the files is being shared between a PC and a Mac. The quickest fix I have found, is to take the pdf and open it in Illustrator and convert all the text to curves. Then it should work correctly.
I don't think anyone has found a definitive answer.
I had this problem on a indesign file designed by someone else. So i opened the file in indesign & selected all element in a page (Ctrl+A) and carefully unselected each visible and required elements. Atlast one null element remained. But i don't know what it is yet, as i'm not the original designer of the indesign file. I deleted the unkown null object. And it worked fine...
Just happened to me on a current Adobe Acrobat DC Pro... Could not even print. Opened in Illustrator, saved as PDF and it's all better. Just FYI. Could not get inDesign to load it.