Urgent Issue:Unable to open SOAP UI Pro(java.lang.NoClassde)

Hi,

I am unable to open SOAP UI.
I am getting following exception error when trying to open SOAP UI via short cut link.

Error:
java.lang.NoClassDefFoundError: com/eviware/soapui/support/SoapUIException
at java.lang.Class.getDeclaredMethods0(Native Method)
at java.lang.Class.privateGetDeclaredMethods(Unknown Source)
at java.lang.Class.getDeclaredMethod(Unknown Source)
at com.exe4j.runtime.LauncherEngine.launch(Unknown Source)
at com.exe4j.runtime.WinLauncher.main(Unknown Source)
Caused by: java.lang.ClassNotFoundException: com.eviware.soapui.support.SoapUIException
at java.net.URLClassLoader$1.run(Unknown Source)
at java.net.URLClassLoader$1.run(Unknown Source)
at java.security.AccessController.doPrivileged(Native Method)
at java.net.URLClassLoader.findClass(Unknown Source)
at java.lang.ClassLoader.loadClass(Unknown Source)
at sun.misc.Launcher$AppClassLoader.loadClass(Unknown Source)
at java.lang.ClassLoader.loadClass(Unknown Source)
... 5 more

Also tried to open via direct link from 'C:\Program Files (x86)\SmartBear\soapUI-Pro-4.5.1'.

I would really appreciate if i get any help here....