According to this page, Hudson requires JRE 1.5 or greater:
http://hudson.gotdns.com/wiki/display/JENKINS/Installation+and+Execution
When trying to start a build using 1.5, I got:
java.lang.NoSuchMethodError: java.util.concurrent.TimeUnit.toHours(J)J
(full trace below)
This is a 1.6 only method, according to:
http://java.sun.com/javase/6/docs/api/java/util/concurrent/TimeUnit.html#toHours(long)
Running on 1.6 works.

When refreshing the page after this error, I get a blank page. This is bad, as
it can turn off users even before they try Hudson

Status Code: 500
Exception:
Stacktrace:

org.apache.commons.jelly.JellyTagException: jar:file:/C:/Documents and
Settings/jamison/.hudson/war/WEB-INF/lib/hudson-core-1.261.jar!/lib/hudson/buildProgressBar.jelly:10:90:
java.util.concurrent.TimeUnit.toHours(J)J
at org.apache.commons.jelly.impl.TagScript.handleException(TagScript.java:713)
at org.apache.commons.jelly.impl.TagScript.run(TagScript.java:282)
at org.apache.commons.jelly.impl.ScriptBlock.run(ScriptBlock.java:95)
at org.apache.commons.jelly.TagSupport.invokeBody(TagSupport.java:186)
at org.apache.commons.jelly.tags.core.JellyTag.doTag(JellyTag.java:45)
at org.apache.commons.jelly.impl.TagScript.run(TagScript.java:262)
at org.apache.commons.jelly.impl.DynamicTag.doTag(DynamicTag.java:80)
at org.apache.commons.jelly.impl.TagScript.run(TagScript.java:262)
at org.apache.commons.jelly.impl.ScriptBlock.run(ScriptBlock.java:95)
at org.apache.commons.jelly.TagSupport.invokeBody(TagSupport.java:186)
at org.apache.commons.jelly.impl.StaticTag.doTag(StaticTag.java:65)
at org.apache.commons.jelly.impl.StaticTagScript.run(StaticTagScript.java:112)
at org.apache.commons.jelly.impl.ScriptBlock.run(ScriptBlock.java:95)
at org.apache.commons.jelly.TagSupport.invokeBody(TagSupport.java:186)
at org.apache.commons.jelly.impl.StaticTag.doTag(StaticTag.java:65)
at org.apache.commons.jelly.impl.StaticTagScript.run(StaticTagScript.java:112)
at org.apache.commons.jelly.impl.ScriptBlock.run(ScriptBlock.java:95)
at org.apache.commons.jelly.TagSupport.invokeBody(TagSupport.java:186)
at org.apache.commons.jelly.impl.StaticTag.doTag(StaticTag.java:65)
at org.apache.commons.jelly.impl.StaticTagScript.run(StaticTagScript.java:112)
at org.apache.commons.jelly.impl.ScriptBlock.run(ScriptBlock.java:95)
at org.apache.commons.jelly.TagSupport.invokeBody(TagSupport.java:186)
at org.apache.commons.jelly.impl.StaticTag.doTag(StaticTag.java:65)
at org.apache.commons.jelly.impl.StaticTagScript.run(StaticTagScript.java:112)
at org.apache.commons.jelly.impl.ScriptBlock.run(ScriptBlock.java:95)
at org.apache.commons.jelly.TagSupport.invokeBody(TagSupport.java:186)
at org.apache.commons.jelly.impl.StaticTag.doTag(StaticTag.java:65)
at org.apache.commons.jelly.impl.StaticTagScript.run(StaticTagScript.java:112)
at org.apache.commons.jelly.impl.ScriptBlock.run(ScriptBlock.java:95)
at org.apache.commons.jelly.TagSupport.invokeBody(TagSupport.java:186)
at org.apache.commons.jelly.tags.core.IfTag.doTag(IfTag.java:42)
at org.apache.commons.jelly.impl.TagScript.run(TagScript.java:262)
at org.apache.commons.jelly.impl.ScriptBlock.run(ScriptBlock.java:95)
at org.apache.commons.jelly.TagSupport.invokeBody(TagSupport.java:186)
at org.apache.commons.jelly.tags.core.JellyTag.doTag(JellyTag.java:45)
at org.apache.commons.jelly.impl.TagScript.run(TagScript.java:262)
at org.kohsuke.stapler.jelly.IncludeTag.doTag(IncludeTag.java:97)
at org.apache.commons.jelly.impl.TagScript.run(TagScript.java:262)
at org.apache.commons.jelly.impl.ScriptBlock.run(ScriptBlock.java:95)
at org.apache.commons.jelly.TagSupport.invokeBody(TagSupport.java:186)
at org.apache.commons.jelly.tags.core.ForEachTag.doTag(ForEachTag.java:150)
at org.apache.commons.jelly.impl.TagScript.run(TagScript.java:262)
at org.apache.commons.jelly.impl.ScriptBlock.run(ScriptBlock.java:95)
at org.apache.commons.jelly.TagSupport.invokeBody(TagSupport.java:186)
at org.apache.commons.jelly.tags.core.JellyTag.doTag(JellyTag.java:45)
at org.apache.commons.jelly.impl.TagScript.run(TagScript.java:262)
at org.kohsuke.stapler.jelly.IncludeTag.doTag(IncludeTag.java:97)
at org.apache.commons.jelly.impl.TagScript.run(TagScript.java:262)
at org.apache.commons.jelly.impl.ScriptBlock.run(ScriptBlock.java:95)
at org.apache.commons.jelly.TagSupport.invokeBody(TagSupport.java:186)
at org.apache.commons.jelly.tags.core.JellyTag.doTag(JellyTag.java:45)
at org.apache.commons.jelly.impl.TagScript.run(TagScript.java:262)
at org.kohsuke.stapler.jelly.IncludeTag.doTag(IncludeTag.java:97)
at org.apache.commons.jelly.impl.TagScript.run(TagScript.java:262)
at org.apache.commons.jelly.impl.ScriptBlock.run(ScriptBlock.java:95)
at org.apache.commons.jelly.tags.define.InvokeBodyTag.doTag(InvokeBodyTag.java:91)
at org.apache.commons.jelly.impl.TagScript.run(TagScript.java:262)
at org.apache.commons.jelly.impl.ScriptBlock.run(ScriptBlock.java:95)
at org.apache.commons.jelly.TagSupport.invokeBody(TagSupport.java:186)
at org.apache.commons.jelly.impl.StaticTag.doTag(StaticTag.java:65)
at org.apache.commons.jelly.impl.StaticTagScript.run(StaticTagScript.java:112)
at org.apache.commons.jelly.impl.ScriptBlock.run(ScriptBlock.java:95)
at org.apache.commons.jelly.TagSupport.invokeBody(TagSupport.java:186)
at org.apache.commons.jelly.tags.core.JellyTag.doTag(JellyTag.java:45)
at org.apache.commons.jelly.impl.TagScript.run(TagScript.java:262)
at org.apache.commons.jelly.impl.DynamicTag.doTag(DynamicTag.java:80)
at org.apache.commons.jelly.impl.TagScript.run(TagScript.java:262)
at org.apache.commons.jelly.impl.ScriptBlock.run(ScriptBlock.java:95)
at org.apache.commons.jelly.TagSupport.invokeBody(TagSupport.java:186)
at org.apache.commons.jelly.tags.core.JellyTag.doTag(JellyTag.java:45)
at org.apache.commons.jelly.impl.TagScript.run(TagScript.java:262)
at org.kohsuke.stapler.jelly.IncludeTag.doTag(IncludeTag.java:97)
at org.apache.commons.jelly.impl.TagScript.run(TagScript.java:262)
at org.apache.commons.jelly.impl.ScriptBlock.run(ScriptBlock.java:95)
at org.apache.commons.jelly.TagSupport.invokeBody(TagSupport.java:186)
at org.apache.commons.jelly.tags.core.ForEachTag.doTag(ForEachTag.java:150)
at org.apache.commons.jelly.impl.TagScript.run(TagScript.java:262)
at org.apache.commons.jelly.impl.ScriptBlock.run(ScriptBlock.java:95)
at org.apache.commons.jelly.tags.define.InvokeBodyTag.doTag(InvokeBodyTag.java:91)
at org.apache.commons.jelly.impl.TagScript.run(TagScript.java:262)
at org.apache.commons.jelly.impl.ScriptBlock.run(ScriptBlock.java:95)
at org.apache.commons.jelly.TagSupport.invokeBody(TagSupport.java:186)
at org.apache.commons.jelly.tags.core.IfTag.doTag(IfTag.java:42)
at org.apache.commons.jelly.impl.TagScript.run(TagScript.java:262)
at org.apache.commons.jelly.impl.ScriptBlock.run(ScriptBlock.java:95)
at org.apache.commons.jelly.TagSupport.invokeBody(TagSupport.java:186)
at org.apache.commons.jelly.tags.core.JellyTag.doTag(JellyTag.java:45)
at org.apache.commons.jelly.impl.TagScript.run(TagScript.java:262)
at org.apache.commons.jelly.impl.DynamicTag.doTag(DynamicTag.java:80)
at org.apache.commons.jelly.impl.TagScript.run(TagScript.java:262)
at org.apache.commons.jelly.impl.ScriptBlock.run(ScriptBlock.java:95)
at org.apache.commons.jelly.TagSupport.invokeBody(TagSupport.java:186)
at org.apache.commons.jelly.tags.core.JellyTag.doTag(JellyTag.java:45)
at org.apache.commons.jelly.impl.TagScript.run(TagScript.java:262)
at org.kohsuke.stapler.jelly.IncludeTag.doTag(IncludeTag.java:97)
at org.apache.commons.jelly.impl.TagScript.run(TagScript.java:262)
at org.apache.commons.jelly.impl.ScriptBlock.run(ScriptBlock.java:95)
at org.apache.commons.jelly.tags.define.InvokeBodyTag.doTag(InvokeBodyTag.java:91)
at org.apache.commons.jelly.impl.TagScript.run(TagScript.java:262)
at org.apache.commons.jelly.impl.ScriptBlock.run(ScriptBlock.java:95)
at org.apache.commons.jelly.TagSupport.invokeBody(TagSupport.java:186)
at org.apache.commons.jelly.impl.StaticTag.doTag(StaticTag.java:65)
at org.apache.commons.jelly.impl.StaticTagScript.run(StaticTagScript.java:112)
at org.apache.commons.jelly.impl.ScriptBlock.run(ScriptBlock.java:95)
at org.apache.commons.jelly.TagSupport.invokeBody(TagSupport.java:186)
at org.apache.commons.jelly.impl.StaticTag.doTag(StaticTag.java:65)
at org.apache.commons.jelly.impl.StaticTagScript.run(StaticTagScript.java:112)
at org.apache.commons.jelly.impl.ScriptBlock.run(ScriptBlock.java:95)
at org.apache.commons.jelly.TagSupport.invokeBody(TagSupport.java:186)
at org.apache.commons.jelly.impl.StaticTag.doTag(StaticTag.java:65)
at org.apache.commons.jelly.impl.StaticTagScript.run(StaticTagScript.java:112)
at org.apache.commons.jelly.impl.ScriptBlock.run(ScriptBlock.java:95)
at org.apache.commons.jelly.TagSupport.invokeBody(TagSupport.java:186)
at org.apache.commons.jelly.impl.StaticTag.doTag(StaticTag.java:65)
at org.apache.commons.jelly.impl.StaticTagScript.run(StaticTagScript.java:112)
at org.apache.commons.jelly.impl.ScriptBlock.run(ScriptBlock.java:95)
at org.apache.commons.jelly.TagSupport.invokeBody(TagSupport.java:186)
at org.apache.commons.jelly.impl.StaticTag.doTag(StaticTag.java:65)
at org.apache.commons.jelly.impl.StaticTagScript.run(StaticTagScript.java:112)
at org.apache.commons.jelly.impl.ScriptBlock.run(ScriptBlock.java:95)
at org.apache.commons.jelly.TagSupport.invokeBody(TagSupport.java:186)
at org.apache.commons.jelly.impl.StaticTag.doTag(StaticTag.java:65)
at org.apache.commons.jelly.impl.StaticTagScript.run(StaticTagScript.java:112)
at org.apache.commons.jelly.impl.ScriptBlock.run(ScriptBlock.java:95)
at org.apache.commons.jelly.TagSupport.invokeBody(TagSupport.java:186)
at org.apache.commons.jelly.tags.core.JellyTag.doTag(JellyTag.java:45)
at org.apache.commons.jelly.impl.TagScript.run(TagScript.java:262)
at org.apache.commons.jelly.impl.DynamicTag.doTag(DynamicTag.java:80)
at org.apache.commons.jelly.impl.TagScript.run(TagScript.java:262)
at org.apache.commons.jelly.impl.ScriptBlock.run(ScriptBlock.java:95)
at org.apache.commons.jelly.TagSupport.invokeBody(TagSupport.java:186)
at org.apache.commons.jelly.tags.core.JellyTag.doTag(JellyTag.java:45)
at org.apache.commons.jelly.impl.TagScript.run(TagScript.java:262)
at
org.kohsuke.stapler.jelly.DefaultScriptInvoker.invokeScript(DefaultScriptInvoker.java:29)
at
org.kohsuke.stapler.jelly.JellyClassTearOff.serveIndexJelly(JellyClassTearOff.java:42)
at org.kohsuke.stapler.jelly.JellyFacet.handleIndexRequest(JellyFacet.java:67)
at org.kohsuke.stapler.Stapler.invoke(Stapler.java:398)
at org.kohsuke.stapler.MetaClass$6.doDispatch(MetaClass.java:173)
at org.kohsuke.stapler.NameBasedDispatcher.dispatch(NameBasedDispatcher.java:30)
at org.kohsuke.stapler.Stapler.invoke(Stapler.java:409)
at org.kohsuke.stapler.Stapler.invoke(Stapler.java:352)
at org.kohsuke.stapler.Stapler.service(Stapler.java:112)
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$1.doFilter(PluginServletFilter.java:61)
at hudson.util.PluginServletFilter.doFilter(PluginServletFilter.java:53)
at winstone.FilterConfiguration.execute(FilterConfiguration.java:195)
at winstone.RequestDispatcher.doFilter(RequestDispatcher.java:368)
at hudson.security.HudsonFilter.doFilter(HudsonFilter.java:88)
at winstone.FilterConfiguration.execute(FilterConfiguration.java:195)
at winstone.RequestDispatcher.doFilter(RequestDispatcher.java:368)
at winstone.RequestDispatcher.forward(RequestDispatcher.java:333)
at winstone.RequestHandlerThread.processRequest(RequestHandlerThread.java:244)
at winstone.RequestHandlerThread.run(RequestHandlerThread.java:150)
at java.lang.Thread.run(Unknown Source)
Caused by: java.lang.NoSuchMethodError: java.util.concurrent.TimeUnit.toHours(J)J
at hudson.model.Executor.isLikelyStuck(Executor.java:207)
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at sun.reflect.NativeMethodAccessorImpl.invoke(Unknown Source)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(Unknown Source)
at java.lang.reflect.Method.invoke(Unknown Source)
at
org.apache.commons.jexl.util.introspection.UberspectImpl$VelMethodImpl.invoke(UberspectImpl.java:259)
at org.apache.commons.jexl.parser.ASTMethod.execute(ASTMethod.java:104)
at org.apache.commons.jexl.parser.ASTReference.execute(ASTReference.java:83)
at org.apache.commons.jexl.parser.ASTReference.value(ASTReference.java:57)
at
org.apache.commons.jexl.parser.ASTReferenceExpression.value(ASTReferenceExpression.java:51)
at org.apache.commons.jexl.ExpressionImpl.evaluate(ExpressionImpl.java:80)
at hudson.ExpressionFactory2$JexlExpression.evaluate(ExpressionFactory2.java:71)
at
org.apache.commons.jelly.expression.ExpressionSupport.evaluateRecurse(ExpressionSupport.java:61)
at org.apache.commons.jelly.impl.TagScript.run(TagScript.java:232)
... 155 more

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