We are aware that some Insider Fast users were experiencing a crash when trying to launch Word on version 16.41 (Build 20081200). We were able to resolve this issue but we are still getting reports that users are still crashing on version 16.41 (Build 20081701). This is currently being investigated and will update this thread when we have more information.
We have identified the issue and have been working on getting this fixed in an future update. Once I have more details on the build number that resolves this issue, I'll update the thread again.
This issue should now be resolved. Please make sure you are on the most updated version of Word. Go to Help > Check for Updates.
Thanks for your patience,