The error message says:
which failed to match all (0) response descriptors
This indicates (due to the (0) in the message) that the setupResponseDescriptors method is not being called so no response descriptors are being added to the object manager.
(0)
setupResponseDescriptors
You are attempting to get object at path "venue", but there doesn't appear to be any indication that you have a "venue" object in your JSON.
If you are not using CoreData, be sure Restkit is defined in your Podfile as follows
Podfile
pod 'RestKit/Network', '~> 0.23'pod 'RestKit/ObjectMapping', '~> 0.23'