Hidden content in pdf export
Adobe InDesign CC 2017. While exporting the file into a PDF. In the PDF while searching for a word I found some sort of ghost fields (picture ghostfields.png). Then I found out that the problem is caused by graphics that we use internally. There are mostly more than just one graphic in one Illustrator file (picture illustratorfile.png). It is saved as an ai, not eps. InDesign exports the parts of those graphics that are actually not visible in InDesign (picture error2.png). I could not find out why, or how to solve it. And because of those ghost field you can not search for anything within the pdf. The only solution was to export the pdf, and then print the pdf with adobe pdf to create a new 'clean' pdf.
To the comment below, "Crop image data exceeding frame" does not stop this from happening.
I also have this problem. It doesn't seem to matter what filetype the placed graphic is. I've had it happen for placed PDFs, AI files, and PSDs.
did you check in the PDF-export-options "compression"? There is a box in the lower right, called "[ ] - Bilddaten auf Rahmen beschneiden" (eng. like "Crop image data exceeding frame"
Does that solve your problem?