Error in installing the 'Firebase/Crashlytics' pod in Swift

I am installing the pod 'Firebase/Crashlytics' into my Xcode project. the project configuration is: XCode: 10.3 Swift Version: 4.2 Pod Version: 1.8.0.beta.2

Error after pod install:

[!] CocoaPods could not find compatible versions for pod "Firebase/CoreOnly":
  In snapshot (Podfile.lock):
    Firebase/CoreOnly (= 6.4.0)

  In Podfile:
    Firebase/Auth was resolved to 6.4.0, which depends on
      Firebase/CoreOnly (= 6.4.0)

    Firebase/Crashlytics was resolved to 6.15.0, which depends on
      Firebase/CoreOnly (= 6.15.0)

[!] Automatically assigning platform `iOS` with version `11.0` on target `Projects` because no platform was specified. Please specify a platform for this target in your Podfile. See `https://guides.cocoapods.org/syntax/podfile.html#platform`.

Other pods in my podfile:

# Uncomment the next line to define a global platform for your project

pod 'SwifterSwift'
pod 'AlamofireNetworkActivityIndicator'
pod 'ReachabilitySwift'
pod 'IQKeyboardManagerSwift'
pod 'Nuke'
pod 'FlagPhoneNumber'
pod 'Firebase/Core'
pod 'Firebase/Auth'
pod 'Firebase/Messaging'
pod 'SDDownloadManager'
pod 'Cosmos', '~> 18.0'
pod 'Socket.IO-Client-Swift', '~> 13.2.0'
pod 'SwiftyJSON', '= 4.0'
pod 'AppImageViewer'
pod 'MDGroupAvatarView'
pod 'OpalImagePicker'
pod 'KMPlaceholderTextView', '~> 1.4.0'
pod 'CropViewController'
pod 'GrowingTextView', '0.6.1'
pod 'Firebase/Crashlytics'
end

Solution

This is issue was coming due to diff version of pods because the old firebase pods were not updated and the default new pod are installed with a higher version.

To install new pod and update the old pods

We have to update the cocoa-pods
Update specific pods so that other pods won't be disturbed