Jenkins version 1.553. I am getting below error when i am trying to access my Jenkins server,

hudson.util.HudsonFailedToLoad: org.jvnet.hudson.reactor.ReactorException: java.lang.Error: java.lang.reflect.InvocationTargetException
at hudson.WebAppMain$3.run(WebAppMain.java:234)
Caused by: org.jvnet.hudson.reactor.ReactorException: java.lang.Error: java.lang.reflect.InvocationTargetException
at org.jvnet.hudson.reactor.Reactor.execute(Reactor.java:269)
at jenkins.InitReactorRunner.run(InitReactorRunner.java:44)
at jenkins.model.Jenkins.executeReactor(Jenkins.java:910)
at jenkins.model.Jenkins.<init>(Jenkins.java:809)
at hudson.model.Hudson.<init>(Hudson.java:82)
at hudson.model.Hudson.<init>(Hudson.java:78)
at hudson.WebAppMain$3.run(WebAppMain.java:222)
Caused by: java.lang.Error: java.lang.reflect.InvocationTargetException
at hudson.init.TaskMethodFinder.invoke(TaskMethodFinder.java:109)
at hudson.init.TaskMethodFinder$TaskImpl.run(TaskMethodFinder.java:169)
at org.jvnet.hudson.reactor.Reactor.runTask(Reactor.java:282)
at jenkins.model.Jenkins$7.runTask(Jenkins.java:899)
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:1142)
at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:617)
at java.lang.Thread.run(Thread.java:745)
Caused by: java.lang.reflect.InvocationTargetException
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
at java.lang.reflect.Method.invoke(Method.java:497)
at hudson.init.TaskMethodFinder.invoke(TaskMethodFinder.java:105)
... 8 more
Caused by: java.lang.ArrayIndexOutOfBoundsException: -1
at com.thoughtworks.xstream.core.util.OrderRetainingMap.entrySet(OrderRetainingMap.java:77)
at java.util.HashMap.putMapEntries(HashMap.java:511)
at java.util.HashMap.putAll(HashMap.java:784)
at com.thoughtworks.xstream.core.util.OrderRetainingMap.<init>(OrderRetainingMap.java:36)
at com.thoughtworks.xstream.converters.reflection.FieldDictionary.buildMap(FieldDictionary.java:135)
at com.thoughtworks.xstream.converters.reflection.FieldDictionary.fieldsFor(FieldDictionary.java:76)
at com.thoughtworks.xstream.converters.reflection.PureJavaReflectionProvider.visitSerializableFields(PureJavaReflectionProvider.java:127)
at hudson.util.RobustReflectionConverter.doMarshal(RobustReflectionConverter.java:149)
at hudson.util.RobustReflectionConverter.marshal(RobustReflectionConverter.java:108)
at com.thoughtworks.xstream.core.AbstractReferenceMarshaller.convert(AbstractReferenceMarshaller.java:69)
at com.thoughtworks.xstream.core.TreeMarshaller.convertAnother(TreeMarshaller.java:58)
at com.thoughtworks.xstream.core.TreeMarshaller.convertAnother(TreeMarshaller.java:43)
at com.thoughtworks.xstream.core.TreeMarshaller.start(TreeMarshaller.java:82)
at com.thoughtworks.xstream.core.AbstractTreeMarshallingStrategy.marshal(AbstractTreeMarshallingStrategy.java:37)
at com.thoughtworks.xstream.XStream.marshal(XStream.java:898)
at com.thoughtworks.xstream.XStream.marshal(XStream.java:887)
at com.thoughtworks.xstream.XStream.toXML(XStream.java:860)
at hudson.XmlFile.write(XmlFile.java:178)
at hudson.model.Descriptor.save(Descriptor.java:758)
at hudson.plugins.git.GitTool.onLoaded(GitTool.java:108)
... 13 more

Before 2 days everything was working fine. I have also removed git plugin from /var/lib/jenkins/plugin.