3D models button greyed out

Hi Caroline,

Thanks for posting in our community and I'm glad to help.

Based on the description, it seems like the 3D Models option only greyed out for a specific Word document. If so, here are some details you can check out and kindly share back with us for further troubleshooting.

1.As the 3D models will be converted to images when the file is sent to somewhere like via Outlook. Please make sure the file hasn't been moved recently or other actions that may caused a change of the 3D models in this file. For reference: Get creative with 3D models (microsoft.com)

2.Meanwhile, for this scenario, you can have a try to convert this file to a previous version(like weeks ago) to see if the feature can be recovered. Notice that it needs the AutoSave feature has been turned on before. Kindly check the reference:

View previous versions of Office files (microsoft.com)

Restore a previous version of a file stored in OneDrive (microsoft.com)

3.To exclude any possible influences from add-ins and background programs, kindly give a try with opening this issue file in Office Safe Mode: Open Office apps in safe mode on a Windows PC (microsoft.com).

As a new file can use the 3D Models feature normally, the issue can be more related to the specific file side instead of the Word application side. Hence, you can share the issue file with engineers here so we can test on our environment and investigate the issue further. See: Share OneDrive files and folders (microsoft.com)

Best Regards,

Mia