Reason: CORS preflight channel did not succeed
The CORS request requires preflight, preflighting could not be performed. There are a couple of reasons why preflighting might fail:
- A cross-site request has previously been performed that already did a preflight, and doing the preflight again is not permitted. Make sure your code only preflights once per connection.
- The preflight request suffered any kind of networking error that might ordinarily occur.