http://imagej.273.s1.nabble.com/Unable-to-compile-plugins-with-ImageJ-1-5x-and-Java-1-6-on-windows-tp5018444p5018452.html
> On Apr 5, 2017, at 12:42 PM, Stein Rørvik <
[hidden email]> wrote:
>
> Hello,
>
> I just downloaded a fresh copy of the official stable version of ImageJ (version 1.50i) bundled with 64-bit Java 1.6.0_24
> from
http://wsr.imagej.net/distros/win/ij150-win-jre6.zip>
> Then I tried to compile a small plugin I wrote myself. I got a message that I needed to download Compiler.jar, so I said yes.
>
> Then I get this error message, and the attempt to compile the plugin halts:
> ImageJ 1.50i; Java 1.6.0_24 [64-bit]; Windows 7 6.1; 16MB of 9121MB (<1%)
>
> java.lang.UnsupportedClassVersionError: com/sun/tools/javac/Main : Unsupported major.minor version 52.0
>
> This plugin requires Java 1.8 or later.
>
> Obviously, the latest version of Compiler.jar is not compatible with Java 1.6.
>
> I looked in the plugins directory on the website and tried to download Compiler.jar from
>
>
https://imagej.nih.gov/ij/plugins/compiler/>
> but the problem is the same. The above link seems to point to the same non-working version ImageJ itself downloaded.
>
> Then I tried to copy Compiler.jar from my previous installation of ImageJ 1.5x to the plugin/jars folder and then everything worked as it should. The working Compiler.jar (compatible with java 1.6) has a file date 2015-06-26 (probably meaning that I installed it on that day) and a filesize 1063375 bytes. My previous installation was updated continuously since v1.49, so several files were inherited from the older versions.
>
> So, what is the proper way to deal with this issue?
> Upgrading to the latest version of 1.51x does not help.
> I do not want to use Java 1.8 because the 3D Viewer does not work with that.
>
> The workaroud for me (transfering an old version of the jar file) worked well, but the problem is that I need to distribute the plugin code for someone else to compile, and cannot send them the compatible Compiler.jar as an email attachement since our company security policy blocks any attempt on emailing .jar files.
>
> Perhaps a version of Compiler.jar compatible with Java 1.6 should have been included in the ij150-win-jre6.zip file?
> It seems that a Java 1.6 compatible version of Compiler.jar was included in ij149-jre6-64.zip.
>
> Stein