Android studio 混淆打包错误

全部错误内容：

17:27:20.989 [ERROR] [org.gradle.internal.buildevents.BuildExceptionReporter]
17:27:20.989 [ERROR] [org.gradle.internal.buildevents.BuildExceptionReporter] FAILURE: Build failed with an exception.
17:27:20.989 [ERROR] [org.gradle.internal.buildevents.BuildExceptionReporter]
17:27:20.989 [ERROR] [org.gradle.internal.buildevents.BuildExceptionReporter] * What went wrong:
17:27:20.989 [ERROR] [org.gradle.internal.buildevents.BuildExceptionReporter] Execution failed for task ':app:transformClassesAndResourcesWithProguardForRelease'.
17:27:20.990 [ERROR] [org.gradle.internal.buildevents.BuildExceptionReporter] > Job failed, see logs for details
17:27:20.990 [ERROR] [org.gradle.internal.buildevents.BuildExceptionReporter]
17:27:20.990 [ERROR] [org.gradle.internal.buildevents.BuildExceptionReporter] * Try:
17:27:20.990 [ERROR] [org.gradle.internal.buildevents.BuildExceptionReporter] Run with --stacktrace option to get the stack trace.

求高手

http://blog.csdn.net/pqq_and/article/details/51209973