I upgrated my Jenkins from 2.19 to 2.193.

When I restarted the service I saw a message stating that I needed to update my java  (I was using 1.7). Did that.

Then I saw error in the log about loading the 2 "matrix-auth" and "matrix-project" plugins... then I disabled them. On next restart it complained about other plugins etc. etc.

At the end I disabled ALL the plugins (by renaming all the .jpi to .jpi.disabled). I was expecting to have jenkins starts and then from the GUI update the relevant plugins.

but still, Jenkins still fails to start with this error (full logfile attached):

Running from: /usr/share/jenkins/jenkins.war
2019-09-09 13:24:28.831+0000 [id=1] INFO org.eclipse.jetty.util.log.Log#initialized: Logging initialize d @1300ms to org.eclipse.jetty.util.log.JavaUtilLog
2019-09-09 13:24:29.149+0000 [id=1] INFO winstone.Logger#logInternal: Beginning extraction from war fil e
2019-09-09 13:24:29.225+0000 [id=1] WARNING o.e.j.s.handler.ContextHandler#setContextPath: Empty contextPa th
2019-09-09 13:24:29.382+0000 [id=1] INFO org.eclipse.jetty.server.Server#doStart: jetty-9.4.z-SNAPSHOT; built: 2019-05-02T00:04:53.875Z; git: e1bc35120a6617ee3df052294e433f3a25ce7097; jvm 1.8.0_222-8u222-b10-1~14. 04-b10
2019-09-09 13:24:30.300+0000 [id=1] INFO o.e.j.w.StandardDescriptorProcessor#visitServlet: NO JSP Suppo rt for /, did not find org.eclipse.jetty.jsp.JettyJspServlet
2019-09-09 13:24:30.487+0000 [id=1] INFO o.e.j.s.s.DefaultSessionIdManager#doStart: DefaultSessionIdMan ager workerName=node0
2019-09-09 13:24:30.487+0000 [id=1] INFO o.e.j.s.s.DefaultSessionIdManager#doStart: No SessionScavenger set, using defaults
2019-09-09 13:24:30.500+0000 [id=1] INFO o.e.j.server.session.HouseKeeper#startScavenging: node0 Scaven ging every 600000ms
Jenkins home directory: /var/lib/jenkins found at: EnvVars.masterEnvVars.get("JENKINS_HOME")
{{2019-09-09 13:24:32.010+0000 [id=1] INFO o.e.j.s.handler.ContextHandler#doStart: Started w.@415b0b49{Jenkins v2.194,/,file:///var/cache/jenkins/war/,AVAILABLE}

{/var/cache/jenkins/w ar}

}}
{{2019-09-09 13:24:32.107+0000 [id=1] INFO o.e.j.server.AbstractConnector#doStart: Started ServerConnector@6b143ee9{HTTP/1.1,[http/1.1]}

{0.0.0.0:8080}

}}
2019-09-09 13:24:32.109+0000 [id=1] INFO org.eclipse.jetty.server.Server#doStart: Started @4578ms
2019-09-09 13:24:32.117+0000 [id=20] INFO winstone.Logger#logInternal: Winstone Servlet Engine v4.0 running: controlPort=disabled
2019-09-09 13:24:35.166+0000 [id=26] INFO jenkins.InitReactorRunner$1#onAttained: Started initialization
2019-09-09 13:24:35.280+0000 [id=25] INFO jenkins.InitReactorRunner$1#onAttained: Listed all plugins
2019-09-09 13:24:39.469+0000 [id=26] INFO jenkins.InitReactorRunner$1#onAttained: Prepared all plugins
2019-09-09 13:24:39.486+0000 [id=26] INFO jenkins.InitReactorRunner$1#onAttained: Started all plugins
2019-09-09 13:24:39.630+0000 [id=25] INFO jenkins.InitReactorRunner$1#onAttained: Augmented all extensions
2019-09-09 13:24:39.731+0000 [id=25] SEVERE jenkins.InitReactorRunner$1#onTaskFailed: Failed Loading global config
com.thoughtworks.xstream.mapper.CannotResolveClassException: hudson.security.GlobalMatrixAuthorizationStrategy
{{ at com.thoughtworks.xstream.mapper.DefaultMapper.realClass(DefaultMapper.java:79)}}
{{ at com.thoughtworks.xstream.mapper.MapperWrapper.realClass(MapperWrapper.java:30)}}
{{ at com.thoughtworks.xstream.mapper.DynamicProxyMapper.realClass(DynamicProxyMapper.java:55)}}
{{ at com.thoughtworks.xstream.mapper.MapperWrapper.realClass(MapperWrapper.java:30)}}
{{ at com.thoughtworks.xstream.mapper.PackageAliasingMapper.realClass(PackageAliasingMapper.java:88)}}
{{ at com.thoughtworks.xstream.mapper.MapperWrapper.realClass(MapperWrapper.java:30)}}
{{ at com.thoughtworks.xstream.mapper.ClassAliasingMapper.realClass(ClassAliasingMapper.java:79)}}
{{ at com.thoughtworks.xstream.mapper.MapperWrapper.realClass(MapperWrapper.java:30)}}
{{ at com.thoughtworks.xstream.mapper.MapperWrapper.realClass(MapperWrapper.java:30)}}
{{ at com.thoughtworks.xstream.mapper.MapperWrapper.realClass(MapperWrapper.java:30)}}
{{ at com.thoughtworks.xstream.mapper.MapperWrapper.realClass(MapperWrapper.java:30)}}
{{ at com.thoughtworks.xstream.mapper.MapperWrapper.realClass(MapperWrapper.java:30)}}
{{ at com.thoughtworks.xstream.mapper.MapperWrapper.realClass(MapperWrapper.java:30)}}
{{ at com.thoughtworks.xstream.mapper.ArrayMapper.realClass(ArrayMapper.java:74)}}
{{ at com.thoughtworks.xstream.mapper.MapperWrapper.realClass(MapperWrapper.java:30)}}
{{ at com.thoughtworks.xstream.mapper.MapperWrapper.realClass(MapperWrapper.java:30)}}
{{ at com.thoughtworks.xstream.mapper.MapperWrapper.realClass(MapperWrapper.java:30)}}
{{ at com.thoughtworks.xstream.mapper.MapperWrapper.realClass(MapperWrapper.java:30)}}
{{ at com.thoughtworks.xstream.mapper.MapperWrapper.realClass(MapperWrapper.java:30)}}
{{ at com.thoughtworks.xstream.mapper.MapperWrapper.realClass(MapperWrapper.java:30)}}
{{ at com.thoughtworks.xstream.mapper.SecurityMapper.realClass(SecurityMapper.java:71)}}
{{ at com.thoughtworks.xstream.mapper.MapperWrapper.realClass(MapperWrapper.java:30)}}
{{ at com.thoughtworks.xstream.mapper.MapperWrapper.realClass(MapperWrapper.java:30)}}
{{ at com.thoughtworks.xstream.mapper.MapperWrapper.realClass(MapperWrapper.java:30)}}
{{ at hudson.util.XStream2$CompatibilityMapper.realClass(XStream2.java:379)}}
{{ at com.thoughtworks.xstream.mapper.MapperWrapper.realClass(MapperWrapper.java:30)}}
{{ at hudson.util.xstream.MapperDelegate.realClass(MapperDelegate.java:43)}}
{{ at com.thoughtworks.xstream.mapper.MapperWrapper.realClass(MapperWrapper.java:30)}}
{{ at com.thoughtworks.xstream.mapper.CachingMapper.realClass(CachingMapper.java:48)}}
{{ at hudson.util.RobustReflectionConverter.determineType(RobustReflectionConverter.java:459)}}
{{ at hudson.util.RobustReflectionConverter.doUnmarshal(RobustReflectionConverter.java:325)}}
Caused: jenkins.util.xstream.CriticalXStreamException: hudson.security.GlobalMatrixAuthorizationStrategy : hudson.security.GlobalMatrixAuthorizationStrategy
---- Debugging information ----
message : hudson.security.GlobalMatrixAuthorizationStrategy
cause-exception : com.thoughtworks.xstream.mapper.CannotResolveClassException
cause-message : hudson.security.GlobalMatrixAuthorizationStrategy
class : hudson.model.Hudson
required-type : hudson.model.Hudson
converter-type : hudson.util.RobustReflectionConverter
path : /hudson/authorizationStrategy
line number : 8
version : not available
-------------------------------

 

This part seems especially surprising to me:

Caused: java.io.IOException: Unable to read /var/lib/jenkins/config.xml

As I verified that this config file exists and is readable for everyone.}}{{

I'm completely stuck now and it's becoming really a problem as I have no idea what to do next.