Processing an uploaded Zip File in Azure Blob Storage

I have an Azure function that gets triggered when a blob gets uploaded to a certain directory. It processes a zip file. When I upload the file to the container with the Azure storage explorer, it works perfectly. When I upload it through web API, it blows up. If I down load that file it seems to be corrupt, however, it is the same size as the source, and when I do a beyond compare between the 2, then seem, identical (and beyond compare seems to see the contents of the zip file).

Here is the upload code:

public async Task<UploadedFileDescription> StoreCatalog(HttpRequestMessage Request)
{
    UploadedFileDescription upload = new UploadedFileDescription();  // my return description
    var guidString = Guid.NewGuid().ToString();
    string fileName = guidString + ".zip";  //add the .zip extenstion
    upload.fileName = fileName;
    string storageConnection = CloudConfigurationManager.GetSetting("StorageConnectionString");
    CloudStorageAccount cloudStorageAccount = CloudStorageAccount.Parse(storageConnection);
    CloudBlobClient cloudBlobClient = cloudStorageAccount.CreateCloudBlobClient();
    CloudBlobContainer cloudBlobContainer = cloudBlobClient.GetContainerReference("uploadedzips");
    CloudBlockBlob cloudBlockBlob = cloudBlobContainer.GetBlockBlobReference(fileName);
    cloudBlockBlob.Properties.ContentType = "application/x-zip-compressed";
    var stream = await Request.Content.ReadAsStreamAsync();
    cloudBlockBlob.UploadFromStream(stream);
    return upload;
}

The file gets into blob storage fine.

Then the triggered Azure function fires and blows up on this line:

ZipArchive archive = new ZipArchive(myBlob);
CloudStorageAccount storageAccount = CloudStorageAccount.Parse(destinationStorage);
CloudBlobClient blobClient = storageAccount.CreateCloudBlobClient();
CloudBlobContainer container = blobClient.GetContainerReference(destinationContainer);

var catalogService = Helpers.container.Resolve<ICatalogService>();
foreach (ZipArchiveEntry file in archive.Entries)    <------blows up here with the msg

System.IO.InvalidDataException
  HResult=0x80131501
  Message=Number of entries expected in End Of Central Directory does not correspond to number of entries in Central Directory.
  Source=System.IO.Compression
  StackTrace:
   at System.IO.Compression.ZipArchive.ReadCentralDirectory()
   at System.IO.Compression.ZipArchive.get_Entries()
   at DentaCAD.AzureFunctions.ProcessUploadedZip.Run(Stream myBlob, String name, TraceWriter log) in C:\repo\ProcessUploadedZip.cs:line 35
   at Microsoft.Azure.WebJobs.Host.Executors.VoidMethodInvoker`2.InvokeAsync(TReflected instance, Object[] arguments)
   at Microsoft.Azure.WebJobs.Host.Executors.FunctionInvoker`2.<InvokeAsync>d__9.MoveNext()

When that line gets hit when uploading the file manually, there are 163 entries in the archive (all small jpg files)

Any thoughts?

it could be a matter of the wrong MIME type. try changing the content type to "application/zip" instead of "application/x-zip-compressed"