"Java.exe" exited with code 1 (Proguard issue)

Question

I get the following error when I build my Xamarin.Android app in Release.

"Java.exe" exited with code 1

Here is the output...

...    
1> java.io.IOException: Can't read [C:\Users\FranciscoJavier\AppData\Local\Android\android-sdk\platforms\android-24\android.jar] (Can't process class [java/nio/charset/CharsetDecoder.class] (Unsupported class version number [52.0] (maximum 51.0, Java 1.7)))
1> at proguard.InputReader.readInput(InputReader.java:230)
1> at proguard.InputReader.readInput(InputReader.java:200)
1> at proguard.InputReader.readInput(InputReader.java:178)
1> at proguard.InputReader.execute(InputReader.java:100)
1> at proguard.ProGuard.readInput(ProGuard.java:196)
1> at proguard.ProGuard.execute(ProGuard.java:78)
1> at proguard.ProGuard.main(ProGuard.java:492)
1> Caused by: java.io.IOException: Can't process class [java/nio/charset/CharsetDecoder.class] (Unsupported class version number [52.0] (maximum 51.0, Java 1.7))
1> at proguard.io.ClassReader.read(ClassReader.java:112)
1> at proguard.io.FilteredDataEntryReader.read(FilteredDataEntryReader.java:87)
1> at proguard.io.JarReader.read(JarReader.java:65)
1> at proguard.io.DirectoryPump.readFiles(DirectoryPump.java:65)
1> at proguard.io.DirectoryPump.pumpDataEntries(DirectoryPump.java:53)
1> at proguard.InputReader.readInput(InputReader.java:226)
1> ... 6 more
1> Caused by: java.lang.UnsupportedOperationException: Unsupported class version number [52.0] (maximum 51.0, Java 1.7)
1> at proguard.classfile.util.ClassUtil.checkVersionNumbers(ClassUtil.java:140)
1> at proguard.classfile.io.LibraryClassReader.visitLibraryClass(LibraryClassReader.java:89)
1> at proguard.classfile.LibraryClass.accept(LibraryClass.java:301)
1> at proguard.io.ClassReader.read(ClassReader.java:86)
1> ... 11 more
1> Picked up JAVA_TOOL_OPTIONS: -Dfile.encoding=UTF8
1>C:\Program Files (x86)\MSBuild\Xamarin\Android\Xamarin.Android.Common.targets(2118,3): error MSB6006: "java.exe" exited with code 1.
1>Done executing task "Proguard" -- FAILED.
1>Done building target "_CompileToDalvikWithDx" in project "Elfo.VisionShop.Droid.csproj" -- FAILED.
1>
1>Build FAILED.

Reading the output messages it seems there is a problem with ProGuard, somebody know what can I do?

Answer 1

Just update proguard from official site http://proguard.sourceforge.net/ (replace folder in $SDK_DIR/tools/proguard/)

Answer 2

You can see the problem here:

Caused by: java.io.IOException: Can't process class [java/nio/charset/CharsetDecoder.class] (Unsupported class version number [52.0] (maximum 51.0, Java 1.7))

Solution: Change your Java target to 7 (1.7).

Answer 3

**Error : while running app “Java.exe” exited with code**

I resolved this by manually overriding the java heap size: In Visual Studio:

1. Right-click on Project
2. Click on Android properties
3. Click on Android Options
4. Select Advanced tab then Advanced android build settings
5. Set Java Max Heap Size to 1G (or larger if needed)

The project now builds.

Answer 4

Having the same problem, for me the following worked (well it's a specific situation causing this error - might be not the only one):

Set Build Log verbosity to Detailed: in VS2017 -> Tools -> Options -> Projects and Solutions -> Build and Run ->MSBuild project build output verbosity -> Detailed (minimum)

Start a build. In output log (eg. in output window) search for

proguard.ParseException:

if the log contains something like:

proguard.ParseException: Unknown option '´╗┐-keep' in line 1 of file 'proguard.cfg'

then simply open your file in a text editor and save it without BOM.

eg. in Notepad++ Encoding -> Encode in UTF8 (make sure not to select Encode in UTF8-BOM) ...and save

Rebuild your project/solution. It should work - at least it workd for me.