There are 2 solutions to the problem :

1. delete office and reinstall office 365.

2. Following these steps:
2.1 Sign out of your account and close all office applications.
2.2 Open Users Library folder (Cmd+shift+G) > Open Group Containers > Move the following files to Trash               (Cmd+Delete) if they are present :
2.3 Sign in again and reopen your office365 applications, they should work without crashing now.