I've run into similar issues with PDFs that open fine in one version of Reader but fail in another. In many cases, updating Acrobat or re-saving the file with a different PDF compatibility setting solved it, though not always. It would definitely help if Adobe provided a clearer error message explaining why the file can't be opened. For anyone working with PDFs regularly, understanding grading reports or other PDF-based documents can also be easier with tools like https://grades-calculator.us/, especially when you need quick calculations alongside your files. Hopefully Adobe improves compatibility across versions.
I've run into similar issues with PDFs that open fine in one version of Reader but fail in another. In many cases, updating Acrobat or re-saving the file with a different PDF compatibility setting solved it, though not always. It would definitely help if Adobe provided a clearer error message explaining why the file can't be opened. For anyone working with PDFs regularly, understanding grading reports or other PDF-based documents can also be easier with tools like https://grades-calculator.us/, especially when you need quick calculations alongside your files. Hopefully Adobe improves compatibility across versions.