I got this exception when I run my application. It happens also in the real Azure blob storage.
I\'ve caught with Fiddler the request that creates this problem:
One thing that comes to mind is that the ETag in
If-Match: 0x8CDA190BD304DD0
is malformed; a valid (strong) etag is always in double quotes.
Dunno whether this has something to do with your problem, though.