xCode build with Google play games plugin

Hello, all.

I recently have problems related play-games-plugin in xCode.
It used to work in last week but it suddenly causes following problems and fails to complile.

Here are my project stauts.

xCode version 8
Unity version 5.3.4p5
Google play game unity for Unity version 0.9.31
Cocoapods applied for xCode project with following settings.

platform :ios, '7.0'

target 'Unity-iPhone' do
pod 'GooglePlayGames', '~> 5.0'
end

post_install do |installer|...

xCode build with Google play games plugin