MWS issue while restarting

Hi,

when we installed MWS, first time it started without any errors, but when we restart the MWS it is showing the following errors

[COLOR=#1f497d](Framework : FATAL) - [POP.001.0002] A “{0}” occurred with the Message “{1}”
java.lang.NoClassDefFoundError: com/webmethods/portal/portlet/wm_discotres_common/IForumConstants

Oracle version: 9.2.0.6 and MWS: 7.1.3

Can you please have a look and help us.

Thanks,
Narendra.
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