Exception in thread "Thread-8" java.lang.NoClassDefFoundError: Could not initialize class com.jacob.com.ComThread
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I'm working on a project of the electronic signature.
When I run the application  I get this message.

run:
log4j:WARN No appenders could be found for logger (com.adesium.mysign.gui.MainForm).
log4j:WARN Please initialize the log4j system properly.
License about to read: MySignProtection
License is available: C:\Documents and Settings\Administrateur\.mysignprotection\mysignprotection.key
Exception in thread "Thread-8" java.lang.NoClassDefFoundError: Could not initialize class com.jacob.com.ComThread
	at idainfront.pdfcreator4j.PdfCreatorApi.<init>(PdfCreatorApi.java:50)
	at com.adesium.mysign.converter.plugins.PdfCreatorConverter.isReady(PdfCreatorConverter.java:103)
	at com.adesium.mysign.converter.plugins.PdfCreatorIsAvalaible.command(PdfCreatorIsAvalaible.java:25)
	at com.adesium.mysign.util.Timeout$TimeoutThread.run(Timeout.java:15)
	at java.lang.Thread.run(Thread.java:619)
thinks,

I use Tomcat 4, and jdk6
could you help me to solve this problem.