Hey Tom!
Thanks for replying. And.. Sorry for the clumsy phrasing of the question.
I am using the standard Preview application to read, comment, and mark PDF documents.
While some aren't, most documents are, from the get go, scanned and/or shared with the searchable/editable text.
For some reason, ever since I've upgraded to Sierra, after a restart of the computer some of these documents (that were downloaded as searchable/editable texts) open as 'flat' files.
This has happened to me on several different cases of scanned texts from different sources.
As if the program corrupts the OCR data in the document.
I know that my problem probably sounds super anal and out-there.But up until now the edit and search options in OSX's Preview were straight up crucial for my studies and research.
I fear that this bug might truly hurt the efficiency of my work that was previously afforded by the rich features of Preview.