Hi,

I've been bitten by this too. No idea why the configs changed. Removing the <launcher> tag sorted the problem for me too.

Kolos

This is a blocker for us. We recently switched to using RVM ruby in jenkins instead of embedded Omnibus ruby (chef).
Somehow it adds to the job:
<launcher ruby-class="Jenkins::Launcher" pluginid="rvm">
<native ruby-class="Java::Hudson::LocalLauncher" pluginid="rvm"/>
</launcher>
and job disappears.
In the jenkins log, we can see:
=====================================
SEVERE: Failed Loading job MyJOBName
hudson.util.IOException2: Unable to read /opt/jenkins/jenkins-home/jobs/MyJOBName/config.xml
at hudson.XmlFile.read(XmlFile.java:147)
at hudson.model.Items.load(Items.java:220)
at jenkins.model.Jenkins$17.run(Jenkins.java:2554)
at org.jvnet.hudson.reactor.TaskGraphBuilder$TaskImpl.run(TaskGraphBuilder.java:146)
at org.jvnet.hudson.reactor.Reactor.runTask(Reactor.java:259)
at jenkins.model.Jenkins$7.runTask(Jenkins.java:888)
at org.jvnet.hudson.reactor.Reactor$2.run(Reactor.java:187)
at org.jvnet.hudson.reactor.Reactor$Node.run(Reactor.java:94)
at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1146)
at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:615)
at java.lang.Thread.run(Thread.java:679)
Caused by: com.thoughtworks.xstream.converters.ConversionException: Undefined class: Java::Hudson::RemoteLauncher : Undefined class: Java::Hudson::RemoteLauncher
---- Debugging information ----
message : Undefined class: Java::Hudson::RemoteLauncher
cause-exception : java.lang.IllegalArgumentException
cause-message : Undefined class: Java::Hudson::RemoteLauncher
class : org.jruby.runtime.builtin.IRubyObject
required-type : org.jruby.runtime.builtin.IRubyObject
converter-type : org.jenkinsci.jruby.JRubyXStreamConverter
path : /project/buildWrappers/ruby-proxy-object/ruby-object/object/launcher/native
line number : 162
class[1] : org.jenkinsci.jruby.JRubyMapper$DynamicProxy
converter-type[1] : org.jenkinsci.jruby.JavaProxyConverter
class[2] : hudson.util.DescribableList
converter-type[2] : hudson.util.DescribableList$ConverterImpl
class[3] : hudson.model.FreeStyleProject
converter-type[3] : hudson.util.RobustReflectionConverter
version : null
-------------------------------
at com.thoughtworks.xstream.core.TreeUnmarshaller.convert(TreeUnmarshaller.java:79)
at com.thoughtworks.xstream.core.AbstractReferenceUnmarshaller.convert(AbstractReferenceUnmarshaller.java:65)
at com.thoughtworks.xstream.core.TreeUnmarshaller.convertAnother(TreeUnmarshaller.java:66)
at com.thoughtworks.xstream.core.TreeUnmarshaller.convertAnother(TreeUnmarshaller.java:50)
at org.jenkinsci.jruby.JRubyXStreamConverter.unmarshal(JRubyXStreamConverter.java:111)
at com.thoughtworks.xstream.core.TreeUnmarshaller.convert(TreeUnmarshaller.java:72)
at com.thoughtworks.xstream.core.AbstractReferenceUnmarshaller.convert(AbstractReferenceUnmarshaller.java:65)
at com.thoughtworks.xstream.core.TreeUnmarshaller.convertAnother(TreeUnmarshaller.java:66)
at com.thoughtworks.xstream.core.TreeUnmarshaller.convertAnother(TreeUnmarshaller.java:50)
at org.jenkinsci.jruby.JRubyXStreamConverter.unmarshal(JRubyXStreamConverter.java:111)
at com.thoughtworks.xstream.core.TreeUnmarshaller.convert(TreeUnmarshaller.java:72)
at com.thoughtworks.xstream.core.AbstractReferenceUnmarshaller.convert(AbstractReferenceUnmarshaller.java:65)
at com.thoughtworks.xstream.core.TreeUnmarshaller.convertAnother(TreeUnmarshaller.java:66)
at com.thoughtworks.xstream.core.TreeUnmarshaller.convertAnother(TreeUnmarshaller.java:50)
at org.jenkinsci.jruby.JRubyXStreamConverter.unmarshal(JRubyXStreamConverter.java:111)
at com.thoughtworks.xstream.core.TreeUnmarshaller.convert(TreeUnmarshaller.java:72)
at com.thoughtworks.xstream.core.AbstractReferenceUnmarshaller.convert(AbstractReferenceUnmarshaller.java:65)
at com.thoughtworks.xstream.core.TreeUnmarshaller.convertAnother(TreeUnmarshaller.java:66)
at com.thoughtworks.xstream.core.TreeUnmarshaller.convertAnother(TreeUnmarshaller.java:50)
at org.jenkinsci.jruby.JavaProxyConverter.unmarshal(JavaProxyConverter.java:60)
at com.thoughtworks.xstream.core.TreeUnmarshaller.convert(TreeUnmarshaller.java:72)
at com.thoughtworks.xstream.core.AbstractReferenceUnmarshaller.convert(AbstractReferenceUnmarshaller.java:65)
at com.thoughtworks.xstream.core.TreeUnmarshaller.convertAnother(TreeUnmarshaller.java:66)
at com.thoughtworks.xstream.core.TreeUnmarshaller.convertAnother(TreeUnmarshaller.java:50)
at com.thoughtworks.xstream.converters.collections.AbstractCollectionConverter.readItem(AbstractCollectionConverter.java:71)
at hudson.util.CopyOnWriteList$ConverterImpl.unmarshal(CopyOnWriteList.java:193)
at hudson.util.DescribableList$ConverterImpl.unmarshal(DescribableList.java:263)
at com.thoughtworks.xstream.core.TreeUnmarshaller.convert(TreeUnmarshaller.java:72)
at com.thoughtworks.xstream.core.AbstractReferenceUnmarshaller.convert(AbstractReferenceUnmarshaller.java:65)
at com.thoughtworks.xstream.core.TreeUnmarshaller.convertAnother(TreeUnmarshaller.java:66)
at hudson.util.RobustReflectionConverter.unmarshalField(RobustReflectionConverter.java:333)
at hudson.util.RobustReflectionConverter.doUnmarshal(RobustReflectionConverter.java:275)
at hudson.util.RobustReflectionConverter.unmarshal(RobustReflectionConverter.java:222)
at com.thoughtworks.xstream.core.TreeUnmarshaller.convert(TreeUnmarshaller.java:72)
at com.thoughtworks.xstream.core.AbstractReferenceUnmarshaller.convert(AbstractReferenceUnmarshaller.java:65)
at com.thoughtworks.xstream.core.TreeUnmarshaller.convertAnother(TreeUnmarshaller.java:66)
at com.thoughtworks.xstream.core.TreeUnmarshaller.convertAnother(TreeUnmarshaller.java:50)
at com.thoughtworks.xstream.core.TreeUnmarshaller.start(TreeUnmarshaller.java:134)
at com.thoughtworks.xstream.core.AbstractTreeMarshallingStrategy.unmarshal(AbstractTreeMarshallingStrategy.java:32)
at com.thoughtworks.xstream.XStream.unmarshal(XStream.java:1061)
at hudson.util.XStream2.unmarshal(XStream2.java:109)
at com.thoughtworks.xstream.XStream.unmarshal(XStream.java:1045)
at com.thoughtworks.xstream.XStream.fromXML(XStream.java:925)
at hudson.XmlFile.read(XmlFile.java:143)
... 10 more
Caused by: java.lang.IllegalArgumentException: Undefined class: Java::Hudson::RemoteLauncher
at org.jenkinsci.jruby.JRubyXStreamConverter.unmarshal(JRubyXStreamConverter.java:86)
at com.thoughtworks.xstream.core.TreeUnmarshaller.convert(TreeUnmarshaller.java:72)

still present in Jenkins 1.536, rvm 0.4, even on the master. A real blocker...

I'm running into the same issue, consistently. Jobs using the RVM plugin randomly disappear every time we restart the server or reload the configuration, which is a huge headache.

Anyone come up with a workaround? I'm happy to dig in but honestly not even sure where to start. I originally thought it was happening every time a job existed in a failed state but that doesn't seem to be the case.

Also, this and JENKINS-19245 seem to be the same issue.

still happening:
ubuntu, jenkins 1.539, rvm plugin 0.4

Code changed in jenkins
User: Eito Katagiri
Path:
bin/convert.rb
http://jenkins-ci.org/commit/rvm-plugin/033c59eb3916b8f2127b47a16956e7628bbe29c0
Log:
add script to convert class name in config.xml

This is because of updating jenkins-plugin-runtime from 0.1.17 to 0.2.3.
This script also fixes JENKINS-18841.

While the previous commit may clean up existing config files, I think the key to keeping this bug from reoccurring is:
https://github.com/jenkinsci/rvm-plugin/pull/14

See Deprecating non-Java plugins.