Q: Microsoft office will no longer work - (keeps crashing, will not open new documents, cannot save without it crashing etc.)

reset permissions on your hard dirve

https://support.apple.com/en-us/HT201560

and for some reason Apple's link is broken so:

http://www.cnet.com/how-to/repair-disk-permissions-to-speed-up-your-mac/

if that does not work make sure you have the latest update for Mac

https://support.office.com/en-ca/article/Check-for-Office-for-Mac-updates-automa tically-bfd1e497-c24d-4754-92ab-910a4074d7c1

if that fails you may consider reinstalling the product.

Uninstall Office and then reinstall.

Office 2011 Removal

Office 2011 Removal (2)

You should also contact Microsoft for Mac Support and/or post in their forums.  It's where the Mac users who use Microsoft products hang out.