REST API - import .rdl file fails using .NET sdk

[kevinnmo]

Hi

I have an A4 embedded instance set up using Service Principal.

I can import a paginated report .rdl file in a workspace using the PowerBI web ui.

However if I try to import the same .rdl file using the REST API via the .NET sdk using the PostImportWithFileAsyncInGroup it fails with "BadRequest" error with response 

{"error":{"code":"RequestedFileIsEncryptedOrCorrupted","pbi.error":{"code":"RequestedFileIsEncryptedOrCorrupted","parameters":{},"details":[],"exceptionCulprit":1}}}

I am able to import a .pbix successfully.

Does anyone have any ideas what may cause this?

Thanks