Command /Applications/Xcode-beta.app/Contents/Developer/usr/bin/copypng emitted errors but did not return a nonzero exit code to indicate failure

While reading /Users/hskj/Desktop/东城新闻项目/DongchengEducationNews/DongchengEducationNews/东城项目/模块切图/2新闻界面/默认缩略图@3x.png pngcrush caught libpng error:
   
2458240
245202221_237370324375277224_237374256
245370245
245i

Command /Applications/Xcode-beta.app/Contents/Developer/usr/bin/copypng emitted errors but did not return a nonzero exit code to indicate failure

解决方案：把工程中，Compress PNG files 设置为NO即可。