Jenkinsの起動後のエラー

Jenkinsを起動するとブラウザでこんなエラーがでました。
様々なサイトや公式ページに書いてある導入を試しましたがうまく来ません。

環境は以下の通りです。

Ubuntu16.04
Jenkins2.89.4
Java1.8.0

org.xmlpull.v1.XmlPullParserException: only 1.0 is supported as <?xml version not '1.1' (position: START_DOCUMENT seen <?xml version=\'1.1\'... @1:19) 
	at org.xmlpull.mxp1.MXParser.parseXmlDeclWithVersion(MXParser.java:2608)
	at org.xmlpull.mxp1.MXParser.parseXmlDecl(MXParser.java:2592)
	at org.xmlpull.mxp1.MXParser.parsePI(MXParser.java:2466)
	at org.xmlpull.mxp1.MXParser.parseProlog(MXParser.java:1447)
	at org.xmlpull.mxp1.MXParser.nextImpl(MXParser.java:1395)
	at org.xmlpull.mxp1.MXParser.next(MXParser.java:1093)
	at com.thoughtworks.xstream.io.xml.XppReader.pullNextEvent(XppReader.java:109)
Caused: com.thoughtworks.xstream.io.StreamException:  : only 1.0 is supported as <?xml version not '1.1' (position: START_DOCUMENT seen <?xml version=\'1.1\'... @1:19) 
	at com.thoughtworks.xstream.io.xml.XppReader.pullNextEvent(XppReader.java:124)
	at com.thoughtworks.xstream.io.xml.AbstractPullReader.readRealEvent(AbstractPullReader.java:148)
	at com.thoughtworks.xstream.io.xml.AbstractPullReader.readEvent(AbstractPullReader.java:141)
	at com.thoughtworks.xstream.io.xml.AbstractPullReader.move(AbstractPullReader.java:118)
	at com.thoughtworks.xstream.io.xml.AbstractPullReader.moveDown(AbstractPullReader.java:103)
	at com.thoughtworks.xstream.io.xml.XppReader.<init>(XppReader.java:63)
	at com.thoughtworks.xstream.io.xml.AbstractXppDriver.createReader(AbstractXppDriver.java:54)
	at com.thoughtworks.xstream.io.xml.AbstractXppDriver.createReader(AbstractXppDriver.java:65)
	at hudson.XmlFile.unmarshal(XmlFile.java:167)
Caused: java.io.IOException: Unable to read /var/lib/jenkins/config.xml
	at hudson.XmlFile.unmarshal(XmlFile.java:169)
	at jenkins.model.Jenkins.loadConfig(Jenkins.java:3067)
	at jenkins.model.Jenkins.access$1200(Jenkins.java:304)
	at jenkins.model.Jenkins$14.run(Jenkins.java:3085)
	at org.jvnet.hudson.reactor.TaskGraphBuilder$TaskImpl.run(TaskGraphBuilder.java:169)
	at org.jvnet.hudson.reactor.Reactor.runTask(Reactor.java:282)
	at jenkins.model.Jenkins$5.runTask(Jenkins.java:1068)
	at org.jvnet.hudson.reactor.Reactor$2.run(Reactor.java:210)
	at org.jvnet.hudson.reactor.Reactor$Node.run(Reactor.java:117)
	at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1149)
	at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:624)
	at java.lang.Thread.run(Thread.java:748)
Caused: org.jvnet.hudson.reactor.ReactorException
	at org.jvnet.hudson.reactor.Reactor.execute(Reactor.java:269)
	at jenkins.InitReactorRunner.run(InitReactorRunner.java:47)
	at jenkins.model.Jenkins.executeReactor(Jenkins.java:1102)
	at jenkins.model.Jenkins.<init>(Jenkins.java:904)
	at hudson.model.Hudson.<init>(Hudson.java:86)
	at hudson.model.Hudson.<init>(Hudson.java:82)
	at hudson.WebAppMain$3.run(WebAppMain.java:233)
Caused: hudson.util.HudsonFailedToLoad
	at hudson.WebAppMain$3.run(WebAppMain.java:250)