Hudson = 1.262
Access Control = Active Directory
Authorization = Matrix based Security

I restart Hudson by doing the following:
net stop "Apache Tomcat"
net start "Apache Tomcat"

After a restart, any attempt to access Hudson produces the following error:

org.springframework.beans.factory.BeanCreationException: Error creating bean
with name 'activeDirectory': Instantiation of bean failed; nested exception is
org.springframework.beans.BeanInstantiationException: Could not instantiate bean
class [hudson.plugins.active_directory.ActiveDirectoryAuthenticationProvider]:
Constructor threw exception; nested exception is java.lang.UnsatisfiedLinkError:
Native Library D:\HudsonData\plugins\active-directory\WEB-INF\lib\com4j.dll
already loaded in another classloader
at
org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.instantiateBean(AbstractAutowireCapableBeanFactory.java:917)
at
org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.createBeanInstance(AbstractAutowireCapableBeanFactory.java:873)
at
org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.doCreateBean(AbstractAutowireCapableBeanFactory.java:514)
at
org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory$1.run(AbstractAutowireCapableBeanFactory.java:485)
at java.security.AccessController.doPrivileged(Native Method)
at
org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.createBean(AbstractAutowireCapableBeanFactory.java:455)
at
org.springframework.beans.factory.support.AbstractBeanFactory$1.getObject(AbstractBeanFactory.java:251)
at
org.springframework.beans.factory.support.DefaultSingletonBeanRegistry.getSingleton(DefaultSingletonBeanRegistry.java:169)
at
org.springframework.beans.factory.support.AbstractBeanFactory.getBean(AbstractBeanFactory.java:248)
at
org.springframework.beans.factory.support.AbstractBeanFactory.getBean(AbstractBeanFactory.java:170)
at
org.springframework.beans.factory.support.DefaultListableBeanFactory.preInstantiateSingletons(DefaultListableBeanFactory.java:413)
at
org.springframework.context.support.AbstractApplicationContext.finishBeanFactoryInitialization(AbstractApplicationContext.java:735)
at
org.springframework.context.support.AbstractApplicationContext.refresh(AbstractApplicationContext.java:369)
at
hudson.util.spring.DefaultRuntimeSpringConfiguration.getApplicationContext(DefaultRuntimeSpringConfiguration.java:94)
at hudson.util.spring.BeanBuilder.createApplicationContext(BeanBuilder.java:387)
at
hudson.plugins.active_directory.ActiveDirectorySecurityRealm.createSecurityComponents(ActiveDirectorySecurityRealm.java:57)
at hudson.model.Hudson.setSecurityRealm(Hudson.java:1135)
at hudson.model.Hudson.load(Hudson.java:1483)
at hudson.model.Hudson.(Hudson.java:378)
at hudson.WebAppMain$2.run(WebAppMain.java:156)
Caused by: org.springframework.beans.BeanInstantiationException: Could not
instantiate bean class
[hudson.plugins.active_directory.ActiveDirectoryAuthenticationProvider]:
Constructor threw exception; nested exception is java.lang.UnsatisfiedLinkError:
Native Library D:\HudsonData\plugins\active-directory\WEB-INF\lib\com4j.dll
already loaded in another classloader
at org.springframework.beans.BeanUtils.instantiateClass(BeanUtils.java:98)
at
org.springframework.beans.factory.support.SimpleInstantiationStrategy.instantiate(SimpleInstantiationStrategy.java:61)
at
org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.instantiateBean(AbstractAutowireCapableBeanFactory.java:911)
... 19 more
Caused by: java.lang.UnsatisfiedLinkError: Native Library
D:\HudsonData\plugins\active-directory\WEB-INF\lib\com4j.dll already loaded in
another classloader
at java.lang.ClassLoader.loadLibrary0(Unknown Source)
at java.lang.ClassLoader.loadLibrary(Unknown Source)
at java.lang.Runtime.load0(Unknown Source)
at java.lang.System.load(Unknown Source)
at com4j.COM4J.loadNativeLibrary(COM4J.java:430)
at com4j.COM4J.(COM4J.java:386)
at
hudson.plugins.active_directory.ActiveDirectoryAuthenticationProvider.(ActiveDirectoryAuthenticationProvider.java:45)
at sun.reflect.NativeConstructorAccessorImpl.newInstance0(Native Method)
at sun.reflect.NativeConstructorAccessorImpl.newInstance(Unknown Source)
at sun.reflect.DelegatingConstructorAccessorImpl.newInstance(Unknown Source)
at java.lang.reflect.Constructor.newInstance(Unknown Source)
at org.springframework.beans.BeanUtils.instantiateClass(BeanUtils.java:83)
... 21 more

The only workaround I've found is to:

1. edit config.xml and either set "<useSecurity>false</useSecurity>" or remove
the following element:

<securityRealm
class="hudson.plugins.active_directory.ActiveDirectorySecurityRealm">
<domain></domain>
</securityRealm>

2. Restart Hudson again. It works now, but naturally the security system is
missing.

3. Restore the original config.xml.

4. Restart Hudson a second time. Hudson now works correctly, until the next
restart.