A family of Microsoft word processing software products for creating web, email, and print documents.
Sorry you're dealing with this, especially when it's urgent. This usually happens when Word is signed in with a different or outdated account than the one that owns the file, or when Windows has blocked the file for safety reasons.
Here are some suggestions you can try:
Open a private/incognito browser window, go to onedrive.com and sign in with the email that owns the document. If the file opens there, you can work on it in Word for the web right away, or download a copy to your computer.
In the Word app, go to File > Account and sign out of every account listed. Close Word, restart your computer, then sign back in with the correct email. Old sign-in info can make Word think you don't have access.
If the file is saved on your computer, right-click it > Properties. If you see an Unblock checkbox near the bottom, check it, click Apply, then try opening it again.
If the message mentions an admin or says your sign-in "doesn't meet the criteria," the document is probably under a school or work account. In that case, your school or work IT team will need to give you access.
If none of these work, could you share the exact error message you see (without any personal info)? That would help narrow it down.