Warning:Exception while processing task java.io.FileNotFoundException

Warning:Exception while processing task java.io.FileNotFoundException: app\build\intermediates\proguard-rules\release\aapt_rules.txt (The system cannot find the path specified)
1. Under 'app' module, in build.gradle file.buildTypes:buildTypes { release { minifyEnabled trueproguardFiles getDefaultProguardFile('proguard-android.txt'), 'proguard-rules.pro'}}

Delete blank proguard file. Because I put rules in proguard-rules.pro file, so I delete getDefaultProguardFile('proguard-android.txt'),left only 'proguard-rules.pro'.Just as follows:
buildTypes { release { minifyEnabled trueproguardFiles 'proguard-rules.pro'}}
2.Delete the folder build in Moudle and rebuild.