Bad java version class error on linux

I just got through the maze of installing CellProfiler on a Linux machine, but when I try to run it I get the following error and I never see a window open:

[methornt@hpc-login2 ~/CellProfiler]$ python CellProfiler.py
WARNING:root:Distributed support disabled: please install nuageux
running build_ext
running build_ext
Exception in thread “main” java.lang.UnsupportedClassVersionError: Bad version number in .class file
at java.lang.ClassLoader.defineClass1(Native Method)
at java.lang.ClassLoader.defineClass(ClassLoader.java:620)
at java.security.SecureClassLoader.defineClass(SecureClassLoader.java:124)
at java.net.URLClassLoader.defineClass(URLClassLoader.java:260)
at java.net.URLClassLoader.access$100(URLClassLoader.java:56)
at java.net.URLClassLoader$1.run(URLClassLoader.java:195)
at java.security.AccessController.doPrivileged(Native Method)
at java.net.URLClassLoader.findClass(URLClassLoader.java:188)
at java.lang.ClassLoader.loadClass(ClassLoader.java:306)
at sun.misc.Launcher$AppClassLoader.loadClass(Launcher.java:268)
at java.lang.ClassLoader.loadClass(ClassLoader.java:251)
at java.lang.ClassLoader.loadClassInternal(ClassLoader.java:319)

I have installed the latest java 6 version which the wiki mentions should work. Would this prevent the window from opening though?

Any help will be greatly appreciated!

Brian
(edited to remove redundant signatures)

I found that because I was in (t)csh, my PATH was munged and the system-supplied version of java (1.5) was being used instead of the new 1.6 version I had installed. Now that the java error is not being printed, the process just hangs …

I ran ‘python -v CellProfiler.py’ to get debugging info, but not sure what to do with this, the last few lines being printed is:

/auto/rcf-proj/met1/software/CellProfiler/cellprofiler/modules/tile.pyc matches /auto/rcf-proj/met1/software/CellProfiler/cellprofiler/modules/tile.py

import cellprofiler.modules.tile # precompiled from /auto/rcf-proj/met1/software/CellProfiler/cellprofiler/modules/tile.pyc

/auto/rcf-proj/met1/software/CellProfiler/cellprofiler/modules/unmixcolors.pyc matches /auto/rcf-proj/met1/software/CellProfiler/cellprofiler/modules/unmixcolors.py

import cellprofiler.modules.unmixcolors # precompiled from /auto/rcf-proj/met1/software/CellProfiler/cellprofiler/modules/unmixcolors.pyc

/auto/rcf-proj/met1/software/CellProfiler/cellprofiler/modules/classifypixels.pyc matches /auto/rcf-proj/met1/software/CellProfiler/cellprofiler/modules/classifypixels.py

import cellprofiler.modules.classifypixels # precompiled from /auto/rcf-proj/met1/software/CellProfiler/cellprofiler/modules/classifypixels.pyc

Is there a problem with whatever under-lying parts ‘classifypixels’ uses? What would those be, if anyone knows?

I have seen references to people having problems with ilastik, but my install seems ok as I can get that to launch without a problem and the window is exported to my desktop as expected (I am installing on a remote headnode for a large Linux cluster).

I am not quite sure what to check from here… ‘python Cellprofiler.py’ just hangs forever…

If you’re not using Ilastik, you might try removing ClassifyPixels.py completely - at least that will tell you whether the problem is with ClassifyPixels.py or what comes after. ClassifyPixels does use a number of libraries: pyVigra, QT and pyh5. There’s some chance that it is the first module to introduce those and that the process hangs when one of them starts.