System.Data.SqlClient.SqlException: The DELETE statement conflicted with the REFERENCE constraint "FK_yaf_UserPMessage_yaf_PMessage". The conflict occurred in database "ste0830008131178", table "dbo.yaf_UserPMessage", column 'PMessageID'.
The statement has been terminated.
   at System.Data.SqlClient.SqlConnection.OnError(SqlException exception, Boolean breakConnection)
   at System.Data.SqlClient.SqlInternalConnection.OnError(SqlException exception, Boolean breakConnection)
   at System.Data.SqlClient.TdsParser.ThrowExceptionAndWarning(TdsParserStateObject stateObj)
   at System.Data.SqlClient.TdsParser.Run(RunBehavior runBehavior, SqlCommand cmdHandler, SqlDataReader dataStream, BulkCopySimpleResultSet bulkCopyHandler, TdsParserStateObject stateObj)
   at System.Data.SqlClient.SqlCommand.FinishExecuteReader(SqlDataReader ds, RunBehavior runBehavior, String resetOptionsString)
   at System.Data.SqlClient.SqlCommand.RunExecuteReaderTds(CommandBehavior cmdBehavior, RunBehavior runBehavior, Boolean returnStream, Boolean async)
   at System.Data.SqlClient.SqlCommand.RunExecuteReader(CommandBehavior cmdBehavior, RunBehavior runBehavior, Boolean returnStream, String method, DbAsyncResult result)
   at System.Data.SqlClient.SqlCommand.InternalExecuteNonQuery(DbAsyncResult result, String methodName, Boolean sendToPipe)
   at System.Data.SqlClient.SqlCommand.ExecuteNonQuery()
   at YAF.Classes.Data.DBAccess.ExecuteNonQuery(SqlCommand cmd, Boolean transaction)
   at YAF.Classes.Data.DB.pmessage_delete(Object userPMessageID, Boolean fromOutbox)
   at YAF.Classes.Data.DB.pmessage_delete(Object userPMessageID)
   at YAF.Controls.PMList.DeleteSelected_Click(Object source, EventArgs e)
   at YAF.Controls.ThemeButton.OnClick(EventArgs e)
   at YAF.Controls.ThemeButton.System.Web.UI.IPostBackEventHandler.RaisePostBackEvent(String eventArgument)
   at System.Web.UI.Page.RaisePostBackEvent(IPostBackEventHandler sourceControl, String eventArgument)
   at System.Web.UI.Page.RaisePostBackEvent(NameValueCollection postData)
   at System.Web.UI.Page.ProcessRequestMain(Boolean includeStagesBeforeAsyncPoint, Boolean includeStagesAfterAsyncPoint)

<div class="ajax__tab_xp" id="forum__ctl1_PMTabs" style="visibility:hidden;">
	<div id="forum__ctl1_PMTabs_header">
		<span id="__tab_forum__ctl1_PMTabs_InboxTab">Inbox</span><span id="__tab_forum__ctl1_PMTabs_OutboxTab">Sent Items</span><span id="__tab_forum__ctl1_PMTabs_ArchiveTab">Archive</span>
	</div><div id="forum__ctl1_PMTabs_body">
		<div id="forum__ctl1_PMTabs_InboxTab">
			
            <div id="forum__ctl1_PMTabs_InboxTab_InboxTabUpdatePanel">

				
                
<div>