CFNetwork internal error

Question

I create my own NSURLProtocol with a caching system, and I see this on the console:

4676: Internal CFNetwork error (0xc01a: /SourceCache/CFNetwork_Sim/CFNetwork-609.1.4/Connection/URLConnectionClient.cpp: 558

Any idea what causes this?

There is no indication that any traffic is not being processed correctly at the current point where it is displayed. The response is cached, the server sends back 304, unmodified, and I load the cached response, and then, exiting from another thread, logs this error.

Answer 1

For me it came about when I forgot to install

setHTTPMethod: 

For NSMutableURLRequest