When I copy & paste text, I cannot re-write anything

I downloaded an .ai file from freepik, it converted fine. Now when I copy the text element and paste it, so the font size etc is exactly the same, it wont let me add any words. I can delete the words, but I cannot write. I tried changing the font, but it wont work. I even now keep pressing ADD YOUR TEXT, then making a new text window but it still wont work. Its driving me crazy.