Hi there,
i'm experiencing the same issue. What scares me is that on the System Status all features are green (blobstore feature missing???) and even here Google is not acknowledging the issue and this is going to be a problem going ahead from more than 10 hours now...
Have Google changed something on servers yesterday that broke our code, so it's our fault, or is this a server issue. Transalted: have we to wait to see if the trouble will be resolved or do we need to do some code change (even if on local testing environment all sounds good)?
Martino.