Jenkins installed by coping the downloaded war over the old war in the jenkins folder

When having the TestSwarm plugin installed (jenkins-testswarm-plugin v 1.2), other plugins start throwing errors on the Manage Plugins page. When I delete the jenkins-testswarm-plugin folder and jenkins-testswarm-plugin.jpi, the errors disappear.

Here is a list of plugins I normally have installed/configured:

specifically the errors below:

Exception: org.apache.commons.jelly.JellyTagException: jar:file:/var/cache/jenkins/war/WEB-INF/lib/jenkins-core-1.519.jar!/hudson/PluginManager/installed.jelly:70:56: <j:include> could not include jelly script: jar:file:/var/lib/jenkins/plugins/jenkins-testswarm-plugin/WEB-INF/lib/classes.jar!/index.jelly. Reason: org.apache.commons.jelly.JellyException: Could not parse Jelly script : jar:file:/var/lib/jenkins/plugins/jenkins-testswarm-plugin/WEB-INF/lib/classes.jar!/index.jelly

Stacktrace:
javax.servlet.ServletException: org.apache.commons.jelly.JellyTagException: jar:file:/var/cache/jenkins/war/WEB-INF/lib/jenkins-core-1.519.jar!/hudson/PluginManager/installed.jelly:70:56: <j:include> could not include jelly script: jar:file:/var/lib/jenkins/plugins/jenkins-testswarm-plugin/WEB-INF/lib/classes.jar!/index.jelly. Reason: org.apache.commons.jelly.JellyException: Could not parse Jelly script : jar:file:/var/lib/jenkins/plugins/jenkins-testswarm-plugin/WEB-INF/lib/classes.jar!/index.jelly
at org.kohsuke.stapler.jelly.JellyFacet$1.dispatch(JellyFacet.java:103)
at org.kohsuke.stapler.Stapler.tryInvoke(Stapler.java:677)
at org.kohsuke.stapler.Stapler.invoke(Stapler.java:770)
at org.kohsuke.stapler.MetaClass$3.doDispatch(MetaClass.java:175)
at org.kohsuke.stapler.NameBasedDispatcher.dispatch(NameBasedDispatcher.java:53)
at org.kohsuke.stapler.Stapler.tryInvoke(Stapler.java:677)
at org.kohsuke.stapler.Stapler.invoke(Stapler.java:770)
at org.kohsuke.stapler.Stapler.invoke(Stapler.java:583)
at org.kohsuke.stapler.Stapler.service(Stapler.java:214)
at javax.servlet.http.HttpServlet.service(HttpServlet.java:45)
at winstone.ServletConfiguration.execute(ServletConfiguration.java:248)
at winstone.RequestDispatcher.forward(RequestDispatcher.java:333)
at winstone.RequestDispatcher.doFilter(RequestDispatcher.java:376)
at hudson.util.PluginServletFilter$1.doFilter(PluginServletFilter.java:95)
at hudson.plugins.greenballs.GreenBallFilter.doFilter(GreenBallFilter.java:58)
at hudson.util.PluginServletFilter$1.doFilter(PluginServletFilter.java:98)
at hudson.util.PluginServletFilter.doFilter(PluginServletFilter.java:87)
at winstone.FilterConfiguration.execute(FilterConfiguration.java:194)
at winstone.RequestDispatcher.doFilter(RequestDispatcher.java:366)
at hudson.security.csrf.CrumbFilter.doFilter(CrumbFilter.java:48)
at winstone.FilterConfiguration.execute(FilterConfiguration.java:194)
at winstone.RequestDispatcher.doFilter(RequestDispatcher.java:366)
at hudson.security.ChainedServletFilter$1.doFilter(ChainedServletFilter.java:84)
at hudson.security.ChainedServletFilter.doFilter(ChainedServletFilter.java:76)
at hudson.security.HudsonFilter.doFilter(HudsonFilter.java:164)
at winstone.FilterConfiguration.execute(FilterConfiguration.java:194)
at winstone.RequestDispatcher.doFilter(RequestDispatcher.java:366)
at org.kohsuke.stapler.compression.CompressionFilter.doFilter(CompressionFilter.java:50)
at winstone.FilterConfiguration.execute(FilterConfiguration.java:194)
at winstone.RequestDispatcher.doFilter(RequestDispatcher.java:366)
at hudson.util.CharacterEncodingFilter.doFilter(CharacterEncodingFilter.java:81)
at winstone.FilterConfiguration.execute(FilterConfiguration.java:194)
at winstone.RequestDispatcher.doFilter(RequestDispatcher.java:366)
at winstone.RequestDispatcher.forward(RequestDispatcher.java:331)
at winstone.RequestHandlerThread.processRequest(RequestHandlerThread.java:227)
at winstone.RequestHandlerThread.run(RequestHandlerThread.java:150)
at java.util.concurrent.Executors$RunnableAdapter.call(Executors.java:471)
at java.util.concurrent.FutureTask$Sync.innerRun(FutureTask.java:334)
at java.util.concurrent.FutureTask.run(FutureTask.java:166)
at winstone.BoundedExecutorService$1.run(BoundedExecutorService.java:77)
at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1146)
at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:615)
at java.lang.Thread.run(Thread.java:679)
Caused by: org.apache.commons.jelly.JellyTagException: jar:file:/var/cache/jenkins/war/WEB-INF/lib/jenkins-core-1.519.jar!/hudson/PluginManager/installed.jelly:70:56: <j:include> could not include jelly script: jar:file:/var/lib/jenkins/plugins/jenkins-testswarm-plugin/WEB-INF/lib/classes.jar!/index.jelly. Reason: org.apache.commons.jelly.JellyException: Could not parse Jelly script : jar:file:/var/lib/jenkins/plugins/jenkins-testswarm-plugin/WEB-INF/lib/classes.jar!/index.jelly
at org.apache.commons.jelly.tags.core.IncludeTag.doTag(IncludeTag.java:109)
at org.apache.commons.jelly.impl.TagScript.run(TagScript.java:269)
at org.apache.commons.jelly.TagSupport.invokeBody(TagSupport.java:161)
at org.apache.commons.jelly.tags.core.WhenTag.doTag(WhenTag.java:46)
at org.apache.commons.jelly.impl.TagScript.run(TagScript.java:269)
at org.apache.commons.jelly.impl.ScriptBlock.run(ScriptBlock.java:95)
at org.apache.commons.jelly.TagSupport.invokeBody(TagSupport.java:161)
at org.apache.commons.jelly.tags.core.ChooseTag.doTag(ChooseTag.java:38)
at org.apache.commons.jelly.impl.TagScript.run(TagScript.java:269)
at org.apache.commons.jelly.impl.ScriptBlock.run(ScriptBlock.java:95)
at org.kohsuke.stapler.jelly.ReallyStaticTagLibrary$1.run(ReallyStaticTagLibrary.java:99)
at org.apache.commons.jelly.impl.ScriptBlock.run(ScriptBlock.java:95)
at org.kohsuke.stapler.jelly.ReallyStaticTagLibrary$1.run(ReallyStaticTagLibrary.java:99)
at org.apache.commons.jelly.impl.ScriptBlock.run(ScriptBlock.java:95)
at org.kohsuke.stapler.jelly.ReallyStaticTagLibrary$1.run(ReallyStaticTagLibrary.java:99)
at org.apache.commons.jelly.TagSupport.invokeBody(TagSupport.java:161)
at org.apache.commons.jelly.tags.core.ForEachTag.doTag(ForEachTag.java:150)
at org.apache.commons.jelly.impl.TagScript.run(TagScript.java:269)
at org.apache.commons.jelly.impl.ScriptBlock.run(ScriptBlock.java:95)
at org.apache.commons.jelly.TagSupport.invokeBody(TagSupport.java:161)
at org.apache.commons.jelly.tags.core.OtherwiseTag.doTag(OtherwiseTag.java:41)
at org.apache.commons.jelly.impl.TagScript.run(TagScript.java:269)
at org.apache.commons.jelly.impl.ScriptBlock.run(ScriptBlock.java:95)
at org.apache.commons.jelly.TagSupport.invokeBody(TagSupport.java:161)
at org.apache.commons.jelly.tags.core.ChooseTag.doTag(ChooseTag.java:38)
at org.apache.commons.jelly.impl.TagScript.run(TagScript.java:269)
at org.kohsuke.stapler.jelly.ReallyStaticTagLibrary$1.run(ReallyStaticTagLibrary.java:99)
at org.apache.commons.jelly.impl.ScriptBlock.run(ScriptBlock.java:95)
at org.kohsuke.stapler.jelly.CallTagLibScript$1.run(CallTagLibScript.java:98)
at org.apache.commons.jelly.tags.define.InvokeBodyTag.doTag(InvokeBodyTag.java:91)
at org.apache.commons.jelly.impl.TagScript.run(TagScript.java:269)
at org.apache.commons.jelly.impl.ScriptBlock.run(ScriptBlock.java:95)
at org.apache.commons.jelly.tags.core.CoreTagLibrary$1.run(CoreTagLibrary.java:98)
at org.apache.commons.jelly.impl.ScriptBlock.run(ScriptBlock.java:95)
at org.apache.commons.jelly.tags.core.CoreTagLibrary$2.run(CoreTagLibrary.java:105)
at org.kohsuke.stapler.jelly.CallTagLibScript.run(CallTagLibScript.java:119)
at org.apache.commons.jelly.impl.ScriptBlock.run(ScriptBlock.java:95)
at org.kohsuke.stapler.jelly.CallTagLibScript$1.run(CallTagLibScript.java:98)
at org.apache.commons.jelly.tags.define.InvokeBodyTag.doTag(InvokeBodyTag.java:91)
at org.apache.commons.jelly.impl.TagScript.run(TagScript.java:269)
at org.apache.commons.jelly.impl.ScriptBlock.run(ScriptBlock.java:95)
at org.kohsuke.stapler.jelly.ReallyStaticTagLibrary$1.run(ReallyStaticTagLibrary.java:99)
at org.apache.commons.jelly.impl.ScriptBlock.run(ScriptBlock.java:95)
at org.kohsuke.stapler.jelly.ReallyStaticTagLibrary$1.run(ReallyStaticTagLibrary.java:99)
at org.kohsuke.stapler.jelly.ReallyStaticTagLibrary$1.run(ReallyStaticTagLibrary.java:99)
at org.apache.commons.jelly.impl.ScriptBlock.run(ScriptBlock.java:95)
at org.kohsuke.stapler.jelly.ReallyStaticTagLibrary$1.run(ReallyStaticTagLibrary.java:99)
at org.apache.commons.jelly.impl.ScriptBlock.run(ScriptBlock.java:95)
at org.kohsuke.stapler.jelly.ReallyStaticTagLibrary$1.run(ReallyStaticTagLibrary.java:99)
at org.apache.commons.jelly.impl.ScriptBlock.run(ScriptBlock.java:95)
at org.apache.commons.jelly.tags.core.CoreTagLibrary$2.run(CoreTagLibrary.java:105)
at org.kohsuke.stapler.jelly.CallTagLibScript.run(CallTagLibScript.java:119)
at org.apache.commons.jelly.tags.core.CoreTagLibrary$2.run(CoreTagLibrary.java:105)
at org.kohsuke.stapler.jelly.JellyViewScript.run(JellyViewScript.java:81)
at org.kohsuke.stapler.jelly.DefaultScriptInvoker.invokeScript(DefaultScriptInvoker.java:63)
at org.kohsuke.stapler.jelly.DefaultScriptInvoker.invokeScript(DefaultScriptInvoker.java:53)
at org.kohsuke.stapler.jelly.JellyFacet$1.dispatch(JellyFacet.java:95)
... 42 more
Caused by: org.apache.commons.jelly.JellyException: Could not parse Jelly script : jar:file:/var/lib/jenkins/plugins/jenkins-testswarm-plugin/WEB-INF/lib/classes.jar!/index.jelly
at org.apache.commons.jelly.JellyContext.compileScript(JellyContext.java:549)
at org.apache.commons.jelly.JellyContext.runScript(JellyContext.java:680)
at org.apache.commons.jelly.JellyContext.runScript(JellyContext.java:670)
at org.apache.commons.jelly.JellyContext.runScript(JellyContext.java:646)
at org.apache.commons.jelly.tags.core.IncludeTag.doTag(IncludeTag.java:101)
... 98 more
Caused by: org.apache.commons.jelly.util.SAXParseException: Error at (4, 146) of jar:file:/var/lib/jenkins/plugins/jenkins-testswarm-plugin/WEB-INF/lib/classes.jar!/index.jelly : Unable to create expression: %mandatory.testswarmServerUrl
at org.apache.commons.jelly.parser.XMLParser.createSAXException(XMLParser.java:1245)
at org.apache.commons.jelly.parser.XMLParser.createSAXException(XMLParser.java:1267)
at org.apache.commons.jelly.parser.XMLParser.createTag(XMLParser.java:1075)
at org.apache.commons.jelly.parser.XMLParser.startElement(XMLParser.java:638)
at com.sun.org.apache.xerces.internal.parsers.AbstractSAXParser.startElement(AbstractSAXParser.java:504)
at com.sun.org.apache.xerces.internal.parsers.AbstractXMLDocumentParser.emptyElement(AbstractXMLDocumentParser.java:182)
at com.sun.org.apache.xerces.internal.impl.XMLNSDocumentScannerImpl.scanStartElement(XMLNSDocumentScannerImpl.java:353)
at com.sun.org.apache.xerces.internal.impl.XMLDocumentFragmentScannerImpl$FragmentContentDriver.next(XMLDocumentFragmentScannerImpl.java:2732)
at com.sun.org.apache.xerces.internal.impl.XMLDocumentScannerImpl.next(XMLDocumentScannerImpl.java:625)
at com.sun.org.apache.xerces.internal.impl.XMLNSDocumentScannerImpl.next(XMLNSDocumentScannerImpl.java:116)
at com.sun.org.apache.xerces.internal.impl.XMLDocumentFragmentScannerImpl.scanDocument(XMLDocumentFragmentScannerImpl.java:488)
at com.sun.org.apache.xerces.internal.parsers.XML11Configuration.parse(XML11Configuration.java:819)
at com.sun.org.apache.xerces.internal.parsers.XML11Configuration.parse(XML11Configuration.java:748)
at com.sun.org.apache.xerces.internal.parsers.XMLParser.parse(XMLParser.java:123)
at com.sun.org.apache.xerces.internal.parsers.AbstractSAXParser.parse(AbstractSAXParser.java:1208)
at com.sun.org.apache.xerces.internal.jaxp.SAXParserImpl$JAXPSAXParser.parse(SAXParserImpl.java:525)
at org.apache.commons.jelly.parser.XMLParser.parse(XMLParser.java:292)
at org.apache.commons.jelly.JellyContext.compileScript(JellyContext.java:545)
... 102 more
Caused by: org.apache.commons.jelly.JellyException: Unable to create expression: %mandatory.testswarmServerUrl
at org.apache.commons.jelly.expression.jexl.JexlExpressionFactory.createExpression(JexlExpressionFactory.java:64)
at org.apache.commons.jelly.expression.CompositeExpression.parse(CompositeExpression.java:82)
at org.apache.commons.jelly.TagLibrary.createExpression(TagLibrary.java:120)
at org.apache.commons.jelly.parser.XMLParser.createTag(XMLParser.java:1055)
... 117 more
Caused by: org.apache.commons.jexl.parser.ParseException: Encountered "%" at line 1, column 1.
Was expecting one of:
<EOF>
<INTEGER_LITERAL> ...
<FLOAT_LITERAL> ...
"{" ...
"empty" ...
"(" ...
"size" ...
"-" ...
"~" ...
"!" ...
"not" ...
"null" ...
"true" ...
"false" ...
";" ...
"if" ...
"while" ...
"foreach" ...
"[" ...
<IDENTIFIER> ...
<STRING_LITERAL> ...

at org.apache.commons.jexl.parser.Parser.generateParseException(Parser.java:3621)
at org.apache.commons.jexl.parser.Parser.jj_consume_token(Parser.java:3500)
at org.apache.commons.jexl.parser.Parser.JexlScript(Parser.java:78)
at org.apache.commons.jexl.parser.Parser.parse(Parser.java:34)
at org.apache.commons.jexl.ExpressionFactory.createNewExpression(ExpressionFactory.java:122)
at org.apache.commons.jexl.ExpressionFactory.createExpression(ExpressionFactory.java:100)
at org.apache.commons.jelly.expression.jexl.JexlExpressionFactory.createExpression(JexlExpressionFactory.java:60)
... 120 more