After I added new dependency to my project and run
platform :ios, '8.0'
pod 'AFNetworking', '~> 2.6'
First, try to wrap your pods with target specification, like this:
target 'TargetName' do pod 'Fabric' pod 'Crashlytics' #other pods end
pod installagain and open the workspace created.
You can do the following instructions in order to fix this configuration issue
CocoaPods did not set the base configuration of your project because your project already has a custom config set.
Noneconfiguration set for both Pods-related targets