Removed RODL and _Intf uploads, just in case.
The ProductService.LoadProductPicture is defined as
Binary LoadProductPicture(int ProductId, bool Thumbnail, out int ThumbnailWidth);
.NET does not allow to create async methods (ones that return Task-based results) with
In other words, such method definition would not compile:
Task<Binary> LoadProductPicture(int ProductId, bool Thumbnail, out int ThumbnailWidth);
You need to somehow redefine this method (f.e. return a structure instead of a combination of Binary result and out integer parameter).