Hi Igantius_cheung!
I'm Jen, and I'd be happy to help you out with this issue.
May I know if you have tried repairing the application? Please try repairing your Office installation by following the instructions in the given link below and see if it helps resolve the issue. Let me know if this works.
https://support.microsoft.com/en-us/office/repa...
I hope this information helps. If you have any questions, please let us know and we'll be glad to assist you further.
Best Regards!
Jen :)