https://www.unocha.org/sites/unocha/...%20Final_1.pdf

This link works fine. However, when it's turned into a hyperlink in Word, I can't stop it being converted to:

https://www.unocha.org/sites/unocha/files/Armed Escort Guidelines - Final_1.pdf

This second link does not work when you try to access it through Word, though if you paste it into Chrome, the browser converts the spaces back to %20 and opens the URL. Which means that Word is converting the %20s into spaces which Word itself doesn't recognise for the purpose of accessing URLS...