Since the last security update from Eucalyptus Jenkins isn't able to start any instances. Information about this update can be found here:
https://launchpadlibrarian.net/72465971/eucalyptus_2.0%2Bbzr1241-0ubuntu4.2_amd64.changes

If I try to start an instance I got the following error message:

java.lang.IllegalArgumentException: Failed to invoke public hudson.util.FormValidation hudson.plugins.ec2.SlaveTemplate$DescriptorImpl.doValidateAmi(java.lang.String,java.lang.String,hudson.plugins.ec2.AwsRegion,java.lang.String) throws java.io.IOException,javax.servlet.ServletException
at org.kohsuke.stapler.Function.bindAndInvoke(Function.java:146)
at org.kohsuke.stapler.Function.bindAndInvokeAndServeResponse(Function.java:88)
at org.kohsuke.stapler.MetaClass$1.doDispatch(MetaClass.java:103)
at org.kohsuke.stapler.NameBasedDispatcher.dispatch(NameBasedDispatcher.java:53)
at org.kohsuke.stapler.Stapler.tryInvoke(Stapler.java:561)
at org.kohsuke.stapler.Stapler.invoke(Stapler.java:646)
at org.kohsuke.stapler.MetaClass$12.dispatch(MetaClass.java:373)
at org.kohsuke.stapler.Stapler.tryInvoke(Stapler.java:561)
at org.kohsuke.stapler.Stapler.invoke(Stapler.java:646)
at org.kohsuke.stapler.MetaClass$4.doDispatch(MetaClass.java:195)
at org.kohsuke.stapler.NameBasedDispatcher.dispatch(NameBasedDispatcher.java:53)
at org.kohsuke.stapler.Stapler.tryInvoke(Stapler.java:561)
at org.kohsuke.stapler.Stapler.invoke(Stapler.java:646)
at org.kohsuke.stapler.Stapler.invoke(Stapler.java:477)
at org.kohsuke.stapler.Stapler.service(Stapler.java:159)
at javax.servlet.http.HttpServlet.service(HttpServlet.java:45)
at winstone.ServletConfiguration.execute(ServletConfiguration.java:249)
at winstone.RequestDispatcher.forward(RequestDispatcher.java:335)
at winstone.RequestDispatcher.doFilter(RequestDispatcher.java:378)
at hudson.util.PluginServletFilter$1.doFilter(PluginServletFilter.java:94)
at hudson.plugins.greenballs.GreenBallFilter.doFilter(GreenBallFilter.java:52)
at hudson.util.PluginServletFilter$1.doFilter(PluginServletFilter.java:97)
at hudson.util.PluginServletFilter.doFilter(PluginServletFilter.java:86)
at winstone.FilterConfiguration.execute(FilterConfiguration.java:195)
at winstone.RequestDispatcher.doFilter(RequestDispatcher.java:368)
at hudson.security.csrf.CrumbFilter.doFilter(CrumbFilter.java:47)
at winstone.FilterConfiguration.execute(FilterConfiguration.java:195)
at winstone.RequestDispatcher.doFilter(RequestDispatcher.java:368)
at hudson.security.ChainedServletFilter$1.doFilter(ChainedServletFilter.java:84)
at hudson.security.ChainedServletFilter.doFilter(ChainedServletFilter.java:76)
at hudson.security.HudsonFilter.doFilter(HudsonFilter.java:164)
at winstone.FilterConfiguration.execute(FilterConfiguration.java:195)
at winstone.RequestDispatcher.doFilter(RequestDispatcher.java:368)
at hudson.util.CharacterEncodingFilter.doFilter(CharacterEncodingFilter.java:81)
at winstone.FilterConfiguration.execute(FilterConfiguration.java:195)
at winstone.RequestDispatcher.doFilter(RequestDispatcher.java:368)
at winstone.RequestDispatcher.forward(RequestDispatcher.java:333)
at winstone.RequestHandlerThread.processRequest(RequestHandlerThread.java:244)
at winstone.RequestHandlerThread.run(RequestHandlerThread.java:150)
at java.lang.Thread.run(Thread.java:662)
Caused by: java.lang.IllegalArgumentException: Unable to convert to class hudson.plugins.ec2.AwsRegion
at org.kohsuke.stapler.AnnotationHandler.convert(AnnotationHandler.java:48)
at org.kohsuke.stapler.AnnotationHandler$2.parse(AnnotationHandler.java:94)
at org.kohsuke.stapler.AnnotationHandler$2.parse(AnnotationHandler.java:82)
at org.kohsuke.stapler.AnnotationHandler.handle(AnnotationHandler.java:57)
at org.kohsuke.stapler.Function.bindAndInvoke(Function.java:141)
... 39 more

Before this update everything is running fine.

Regards,
Joachim