It sounds like whoever created the form didn't know what one does at the end to allow it to be a fill in form. I am presuming this thing is a document template, that is, a dotx file, not a docx file, which is a normal word document.
The creator should have put protection on the document template that allows the end user only to fill out forms. After the form fields are filled in it is possible to take all protection off, if that's necessary.
Brian - Windows 10 Home, 64-Bit, Version 1803, Build 17134
A little kindness from person to person is better than a vast love for all humankind.
~ Richard Dehmel