Hello Daniele, It looks as if credentials have not been set properly for your project. How did you set app authentication, exactly, and how did you ascertain it works fine, as you mention? You can gather more detail by reading points a. to h. at Step 1 on the ".NET Quickstart" documentation page. In fact, following the whole example provided on that page may prove generally helpful in your case.
The actual code example on this page is somewhat more elaborate than your example: // Define parameters of request. FilesResource.ListRequest listRequest = service.Files.List(); listRequest.PageSize = 10; listRequest.Fields = "nextPageToken, files(id, name)"; // List files. IList<Google.Apis.Drive.v3.Data.File> files = listRequest.Execute() .Files; You are encouraged to adapt this code snippet for your particular situation, and post the results back here. -- You received this message because you are subscribed to the Google Groups "Google App Engine" group. To unsubscribe from this group and stop receiving emails from it, send an email to google-appengine+unsubscr...@googlegroups.com. To post to this group, send email to google-appengine@googlegroups.com. Visit this group at https://groups.google.com/group/google-appengine. To view this discussion on the web visit https://groups.google.com/d/msgid/google-appengine/ebbd0b7e-121e-4c53-b168-4ad0ae75566c%40googlegroups.com. For more options, visit https://groups.google.com/d/optout.