In my Anroid Java app, I would like to offer users the option of searching for and downloading their files from Onedrive.

After login in, I get the GraphServiceClient.

 final InteractiveBrowserCredential interactiveBrowserCredential = new InteractiveBrowserCredentialBuilder()
       .clientId(CLIENT_ID)
       .redirectUrl(REDIRECT_URL)
       .build();
 final TokenCredentialAuthProvider authProvider = new TokenCredentialAuthProvider(SCOPES, interactiveBrowserCredential);
 final GraphServiceClient graphClient = GraphServiceClient
      .builder()
      .authenticationProvider(authProvider)
      .buildClient();

But when I search for root directory, I get the error:
—> com.microsoft.graph.core.ClientException: Error executing the request

Can anyone help me with this?
Thanks for your help

GGK