Opmanager failed to startup.

Opmanager failed to startup.

Please help, my opmanager failed to startup after the server rebooted.
 
below the wrapper.log
 
STATUS | wrapper  | 2014/12/16 15:59:49 | Starting the ManageEngine OpManager service...
STATUS | wrapper  | 2014/12/16 15:59:49 | --> Wrapper Started as Service
STATUS | wrapper  | 2014/12/16 15:59:49 | Java Service Wrapper Professional Edition 32-bit 3.5.15
STATUS | wrapper  | 2014/12/16 15:59:49 |   Copyright (C) 1999-2012 Tanuki Software, Ltd. All Rights Reserved.
STATUS | wrapper  | 2014/12/16 15:59:49 |     http://wrapper.tanukisoftware.com
STATUS | wrapper  | 2014/12/16 15:59:49 |   Licensed to Zoho Corporation Pvt. Ltd. for ManageEngine OpManager
STATUS | wrapper  | 2014/12/16 15:59:49 |
STATUS | wrapper  | 2014/12/16 15:59:50 | Launching a JVM...
INFO   | jvm 1    | 2014/12/16 15:59:50 | WrapperManager: Initializing...
INFO   | jvm 1    | 2014/12/16 15:59:51 | taryIconProps {DefaultMenuItem=Status, ApplicationName=OpManager, Menu=[{Id=Status, DisplayName=&OpManager Status, RunProcess=ShowOpManagerStatus}, {Id=StartClient, DisplayName=Start &Client, RunProcess=StartOpManagerWebClient}, {Id=ShutDownServer, DisplayName=Sh&ut Down Server, RunProcess=ShutdownOpManager}], EnableIcon=images/logo16x16_green.png, DisableIcon=images/logo16x16_gray.png, ToolTipText=ProductName, MainProcess=StartOpManager}
INFO   | jvm 1    | 2014/12/16 15:59:51 | Windows 2003
INFO   | jvm 1    | 2014/12/16 15:59:51 | application_name OpManager
INFO   | jvm 1    | 2014/12/16 15:59:51 | startAndRun
INFO   | jvm 1    | 2014/12/16 15:59:51 | menuName &OpManager Status RunProcess ShowOpManagerStatus
INFO   | jvm 1    | 2014/12/16 15:59:51 | menuName Start &Client RunProcess StartOpManagerWebClient
INFO   | jvm 1    | 2014/12/16 15:59:51 | menuName Sh&ut Down Server RunProcess ShutdownOpManager
INFO   | jvm 1    | 2014/12/16 15:59:51 | setProcessInProgress true
INFO   | jvm 1    | 2014/12/16 15:59:51 | inside addon check
INFO   | jvm 1    | 2014/12/16 15:59:51 | Error while instantiating Driver - org.postgresql.Driver
INFO   | jvm 1    | 2014/12/16 15:59:51 | java.lang.ClassNotFoundException: org.postgresql.Driver
INFO   | jvm 1    | 2014/12/16 15:59:51 |  at java.net.URLClassLoader$1.run(Unknown Source)
INFO   | jvm 1    | 2014/12/16 15:59:51 |  at java.security.AccessController.doPrivileged(Native Method)
INFO   | jvm 1    | 2014/12/16 15:59:51 |  at java.net.URLClassLoader.findClass(Unknown Source)
INFO   | jvm 1    | 2014/12/16 15:59:51 |  at java.lang.ClassLoader.loadClass(Unknown Source)
INFO   | jvm 1    | 2014/12/16 15:59:51 |  at sun.misc.Launcher$AppClassLoader.loadClass(Unknown Source)
INFO   | jvm 1    | 2014/12/16 15:59:51 |  at java.lang.ClassLoader.loadClass(Unknown Source)
INFO   | jvm 1    | 2014/12/16 15:59:51 |  at java.lang.ClassLoader.loadClassInternal(Unknown Source)
INFO   | jvm 1    | 2014/12/16 15:59:51 |  at java.lang.Class.forName0(Native Method)
INFO   | jvm 1    | 2014/12/16 15:59:51 |  at java.lang.Class.forName(Unknown Source)
INFO   | jvm 1    | 2014/12/16 15:59:51 |  at jdbc.CreateSchema.instantiateDriver(CreateSchema.java:104)
INFO   | jvm 1    | 2014/12/16 15:59:51 |  at jdbc.CreateSchema.init(CreateSchema.java:85)
INFO   | jvm 1    | 2014/12/16 15:59:51 |  at com.adventnet.nms.startnms.NmsMainBE.main(NmsMainBE.java:377)
INFO   | jvm 1    | 2014/12/16 15:59:51 |  at com.adventnet.launcher.nms.StartNmsJdbc.run(StartNmsJdbc.java:236)
INFO   | jvm 1    | 2014/12/16 15:59:51 |  at java.lang.Thread.run(Unknown Source)
INFO   | jvm 1    | 2014/12/16 15:59:51 | Exiting OpManager
STATUS | wrapper  | 2014/12/16 15:59:53 | ManageEngine OpManager started.
STATUS | wrapper  | 2014/12/16 15:59:55 | <-- Wrapper Stopped
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