Hello Stephen Gray,
Thanks for reaching out!
As per the details provided, you're trying to use Download contents of a driveItemVersion graph API in Graph Explorer. For this API, the response content is not available in Graph Explorer due to CORS (Cross-Origin Resource Sharing) policy. You can execute this same endpoint/request in an API client, like Postman and it will work as expected.
Refer this to know about CORS.
Got the CORS error while trying to get the content of DriveItem version using GRAPH API: me/drive/items/{items-id}/versions/{version-id}/content
from Graph Explorer.
Got the successful response from Postman with same API endpoint.
Please note that, we can't get the content of current version using above graph API. To get the content of current version use: me/drive/items/{items-id}/content
Hope this helps.
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