Can no longer create form fields in a PDF document
I created a PDF file from a Word document successfully, and started creating a form out of it by adding various fields: checkboxes and text fields. After attempting to copy and paste a text field that I wanted to have several similar versions of, Acrobat will no longer create a new form field - of any type. I've closed and re-opened the file and the application several times, restarted my Mac, and I just can't add any fields to this PDF file.
I also updated to the latest version of Acrobat Pro DC - same problem.
I can create form fields in different PDF files.
Any thoughts on what is going on with this file?