crash in -[NSURLConnectionVCR connection:didReceiveData]
In the following pair of lines of code, the former is documented to return -1 as the expected content length under certain circumstances. The latter throws an exception when this occurs. Bounds checking expectedContentLength so it is always > 0 fixes the issue.
long long expectedContentLength = [response expectedContentLength]; responseData = [NSMutableData dataWithCapacity:expectedContentLength];