title: java.io.IOException: Can't process class [class path] (Unsupported version number [55.0] (maximum 54.0, Java 10))
body: <p>I'm unable to compile java code that my coworker can successfully compile.</p>
  
  <p>I have JRE 8u221.</p>
  
  <p>Proguard is version 6.03</p>
  
  <p>From my build.bat output:</p>
  
  <p>dist-obfuscate:
       [echo] Extracting Objfuscator
      [unzip] Expanding: c:\Workspaces\abcd\efg\Trunk\ESDE\Scripts\proguard\proguard6.0.3.zip into c:\Workspaces\abcd\efg\Trunk\ESDE\Scripts\proguard
       [echo] Jarring Base ESDE
       [copy] Copying 1 file to c:\Workspaces\abcd\efg\Trunk\ESDE\Scripts\proguard</p>
  
  <pre><code> [java] ProGuard, version 6.0.3java.io.IOException: Can't read [c:\Workspaces\abcd\efg\Trunk\ESDE\Scripts\proguard\sdeIn.jar] (Can't process class [company/application/actions/AboutAction.class] (Unsupported version number [55.0] (maximum 54.0, Java 10)))
  
   [java]
   [java] Reading input...
   [java]     at proguard.InputReader.readInput(InputReader.java:214)Reading program jar [c:\Workspaces\abcd\efg\Trunk\ESDE\Scripts\proguard\sdeIn.jar]
   [java]
   [java]     at proguard.InputReader.readInput(InputReader.java:184)
   [java]     at proguard.InputReader.readInput(InputReader.java:162)
   [java]     at proguard.InputReader.execute(InputReader.java:90)
   [java]     at proguard.ProGuard.readInput(ProGuard.java:255)
   [java]     at proguard.ProGuard.execute(ProGuard.java:96)
   [java]     at proguard.ProGuard.main(ProGuard.java:572)
   [java] Caused by: java.io.IOException: Can't process class [company/application/actions/AboutAction.class] (Unsupported version number [55.0] (maximum 54.0, Java 10))
   [java]     at proguard.io.ClassReader.read(ClassReader.java:114)
   [java]     at proguard.io.FilteredDataEntryReader.read(FilteredDataEntryReader.java:87)
   [java]     at proguard.io.FilteredDataEntryReader.read(FilteredDataEntryReader.java:87)
   [java]     at proguard.io.JarReader.read(JarReader.java:83)
   [java]     at proguard.io.DirectoryPump.readFiles(DirectoryPump.java:65)
   [java]     at proguard.io.DirectoryPump.pumpDataEntries(DirectoryPump.java:53)
   [java]     at proguard.InputReader.readInput(InputReader.java:210)
   [java]     ... 6 more
   [java] Caused by: java.lang.UnsupportedOperationException: Unsupported version number [55.0] (maximum 54.0, Java 10)
   [java]     at proguard.classfile.util.ClassUtil.checkVersionNumbers(ClassUtil.java:148)
   [java]     at proguard.classfile.io.ProgramClassReader.visitProgramClass(ProgramClassReader.java:101)
   [java]     at proguard.classfile.ProgramClass.accept(ProgramClass.java:430)
   [java]     at proguard.io.ClassReader.read(ClassReader.java:91)
   [java]     ... 12 more
   [java] Java Result: 1
  </code></pre>
  
  <p>BUILD FAILED
  c:\Workspaces\abcd\efg\Trunk\ESDE\build.xml:877: Warning: Could not find file c:\Workspaces\abcd\efg\Trunk\ESDE\Scripts\proguard\sde.jar to copy.</p>
  
  <p>Questions:</p>
  
  <p>1) "Version 55.0"?  Version of...what?</p>
  
  <p>Proguard version = 6.0.3.</p>
  
  <p>2) "Java 10"?  Nope.</p>
  
  <p>java -version
  java version "1.8.0_221"
  Java(TM) SE Runtime Environment (build 1.8.0_221-b11)
  Java HotSpot(TM) 64-Bit Server VM (build 25.221-b11, mixed mode)</p>
  
  <p>This is Java <em>8</em>, not 10.</p>