I beleie this happens when making larger documents. So far it has only happened on documents with 500+ text pages or 50+ image pages.
When I go file -> save as, the window asking me where to save appears. But when I enter a location and file name, then clock save, nothing happens. Acrobat does not hang up for even a moment as it normally does when saving a file, and no file appears in the folder I have saved it to. Acrobat just does not do anything.
I have tried alternatives such as clicking save (as this created file is new, it takes me to the same box as save as) and closing the program (it asks if I want to save before closing, and after clicking yes it does the same as save as, only the program does not close afterwards and no file is saved to the location specified).