I have a PDF of a technical paper, and I would like to highlight portions and make notes. However, neither of those tools are enabled in Adobe Reader when I open the file (using Windows 7).
I can select and copy text from the file to paste elsewhere, as well as search the contents. It's just highlighting and sticky notes that appear to not be working.
Why does this happen? Is there any way I can enable highlighting and sticky notes? I keep these files in the cloud and read them across multiple devices, including Windows, Mac OS X, Kindle Fire and an iPhone, so a cross-platform solution would be greatly appreciated.