Could not get unknown property 'release' for SigningConfig container of type org.gradle.api.internal.FactoryNamedDomainObjectContainer

 This error will be thrown when release property is not defined in the SigningConfig.

Add the release property to the build.gradle file when release type is changed to release.

signingConfigs {

     release {

          keyAlias keystoreProperties['keyAlias']

          keyPassword keystoreProperties['keyPassword']

          storeFile keystoreProperties['storeFile'] ? file(keystoreProperties['storeFile']) : null

          storePassword keystoreProperties['storePassword']

     }

 }

buildTypes {

    release {

        signingConfig signingConfigs.release

    }

}