I'm using Adobe Acrobat Reader DC. As of yesterday, when I try to copy and paste a number into a text box on my PDF, the numbers show up as question marks. They appear as numbers in the comment column. I can copy and paste text in from the same website with no problem. It worked fine on Friday, but started doing this on Monday. I've emptied my cache and history. I've reinstalled Adobe Acrobat Reader DC. Nothing seems to work. I've been working with the website and they can't duplicate the problem. Any suggestions?
This is usually caused by a font problem: The glyphs (that's the drawings of the character) for the characters you've pasted are not available in the font that is used to display the text in question.
The fact that you can paste normal text, and this only affects numbers is strange, but does not necessarily rule out a font problem.
What I would try is to save the file with the question marks in it, and then try to open it on a different computer. Does the text display correctly? What about when you bring it back to the first computer and re-open it?