My thesis PDF got flattened somehow and now I can’t edit the text before the deadline on my laptop where nothing new can be installed. How do I undo that?
Flattening usually can’t be undone because the editable layers were discarded. Go back to the original Word or Google Docs file, make the changes there, then export a fresh PDF. If that’s gone, try opening the PDF in Word, but formatting may shift, especially if every page became an image. I learned the hard way to save the source separately before flattening anything.