In Jenkins 2.336, I am not getting LDAP option in Configure Global Security

After upgrading to Jenkins 2.336, I am unable to find LDAP option and if I try to update the plugin of LDAP also, it fails. Is there any other fix or changes I am missing out?

What is the failure message? Have you checked the logs for exceptions?

java.lang.ClassNotFoundException: hudson.tasks.MailAddressResolver
at org.apache.tools.ant.AntClassLoader.findClassInComponents(AntClassLoader.java:1402)
at org.apache.tools.ant.AntClassLoader.findClass(AntClassLoader.java:1357)
at org.apache.tools.ant.AntClassLoader.loadClass(AntClassLoader.java:1112)
at java.lang.ClassLoader.loadClass(ClassLoader.java:351)
Caused: java.lang.NoClassDefFoundError: hudson/tasks/MailAddressResolver
at java.lang.ClassLoader.defineClass1(Native Method)
at java.lang.ClassLoader.defineClass(ClassLoader.java:756)
at org.apache.tools.ant.AntClassLoader.defineClassFromData(AntClassLoader.java:1172)
at org.apache.tools.ant.AntClassLoader.getClassFromStream(AntClassLoader.java:1340)
at org.apache.tools.ant.AntClassLoader.findClassInComponents(AntClassLoader.java:1392)
at org.apache.tools.ant.AntClassLoader.findClass(AntClassLoader.java:1357)
at org.apache.tools.ant.AntClassLoader.loadClass(AntClassLoader.java:1112)
at java.lang.ClassLoader.loadClass(ClassLoader.java:351)
at com.mtvi.plateng.hudson.ldap.PluginImpl.getConfigXml(PluginImpl.java:82)
at com.mtvi.plateng.hudson.ldap.PluginImpl.loadConfiguration(PluginImpl.java:56)
at com.mtvi.plateng.hudson.ldap.PluginImpl.start(PluginImpl.java:44)
at hudson.ClassicPluginStrategy.startPlugin(ClassicPluginStrategy.java:416)
at hudson.ClassicPluginStrategy.load(ClassicPluginStrategy.java:405)
Caused: java.io.IOException: Failed to initialize
at hudson.ClassicPluginStrategy.load(ClassicPluginStrategy.java:408)
at hudson.PluginManager.dynamicLoad(PluginManager.java:927)
Caused: java.io.IOException: Failed to install ldapemail plugin
at hudson.PluginManager.dynamicLoad(PluginManager.java:940)
at hudson.model.UpdateCenter$InstallationJob._run(UpdateCenter.java:2217)
Caused: java.io.IOException: Failed to dynamically deploy this plugin
at hudson.model.UpdateCenter$InstallationJob._run(UpdateCenter.java:2221)
at hudson.model.UpdateCenter$DownloadJob.run(UpdateCenter.java:1867)
at java.util.concurrent.Executors$RunnableAdapter.call(Executors.java:511)
at java.util.concurrent.FutureTask.run(FutureTask.java:266)
at hudson.remoting.AtmostOneThreadExecutor$Worker.run(AtmostOneThreadExecutor.java:121)
at java.lang.Thread.run(Thread.java:748)

whenever I try to update any LDAP plugin, it gives me error

Did you upgrade the Mailer plugin? It looks like that is missing in your instance.