I’m using Microsoft.SharepointOnline.CSOM nugget and I can upload files withput any problems but if I change to ExecuteQueryAsync() method seems to be notworking. Simply program fails without any exception.

Code Example

FileCreationInformation fileCreation = new FileCreationInformation()
{
    ContentStream = new System.IO.MemoryStream(System.IO.File.ReadAllBytes(file.SourceFilePath)),
    Overwrite = true,
    Url = file.FileName
};
var uploadFile = folder.Files.Add(fileCreation);
_clientContext.Load(uploadFile);
await _clientContext.ExecuteQueryAsync();

Same code using ExecuteQuery() is working properly.