File corruption is indeed the most likely cause of your problem. And as MilesAhead already stated, it can be the source.
But you can also consider the actual source of the file. How was the file created and by whom?
PDF is an old standard and there are several iterations of this format. Are you sure the person/organization creating the PDF file, used an iteration of the PDF format that your version of Acrobat DC isn't supporting anymore?
Because in that case, any file repair attempt would be in vain. The only thing to try is opening the PDF file in a different PDF viewer or editor. If the alternative PDF software is able to read the file, you'll know that Acrobat DC is the party-po.per.
Perhaps you could open the problematic PDF file in a (free) PDF editor and store it again, using an PDF iteration that is supported by your Acrobat DC software. When that works, you could mention to the creator of this PDF file that he/she/they should use a different or more modern iteration of the PDF format when they create their PDF file.