Hi,
Thank you for your question in this community. According to your description of the problem, you can follow suggestions to help you solve the problem:
May I ask whether your insert picture function is also grayed out, if so, you can go to: File>Account>Account Privacy>Manage Settings. Then look for the "Enable optional connected experiences" Make sure this option is turned on.
If it fails to solve your problem, you can try to open your file in safe mode to help you solve the problem, which can help us exclude third-party plug-ins from affecting your use。
Open Office apps in safe mode on a Windows PC
If you still cannot insert in safe mode, you can try online repair to repair the inability to insert the video caused by the missing file.
Repair an Office application
If the problem is not resolved, you can provide the following information to help us solve the problem:
1.You can confirm with your admin whether the Group Policy is enabled。
- Please check whether your document is in compatibility mode, see the file name on the top ribbon, is compatibility mode added at the end of file name?
If so, go to File > Info > Convert. And check the result.
Best Regards,
Ethan