Please include the below in the web.config file.
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<configSections>   
     <section name="log4net" type="log4net.Config.Log4NetConfigurationSectionHandler, log4net"/>
</configSections>  

<log4net>
    <root>
      <level value="Debug"/>
      <appender-ref ref="LogFileAppender"/>
    </root>
    <appender name="LogFileAppender" type="log4net.Appender.RollingFileAppender">
      <file value="ClientFolders/%property{ClientFolder}/ImportLog/" />
      <file type="log4net.Util.PatternString" value="ClientFolders/%property{ClientFolder}/ImportLog/ImportLog_%utcdate{ddMMyyyy}.txt" />
      <datePattern value="dd.MM.yyyy'.log'" />
      <staticLogFileName value="false" />
      <appendToFile value="true" />
      <rollingStyle value="Size" />
      <maxSizeRollBackups value="10" />
      <maximumFileSize value="10MB" />
      <layout type="log4net.Layout.PatternLayout">
        <!--<param name="ConversionPattern" value="%[%property{ClientFolder}] %message%newline"/>-->
        <param name="ConversionPattern" value="%[%property{ClientFolder}]%[%property{Task}] %date [%thread] %level %logger - %message%newline"/>
      </layout>
    </appender>
    <logger name="ImportLog">
      <level value="DEBUG"/>
    </logger>
</log4net>



 <appSettings>

    <add key="MI_Mode" value="WEB"/> <!-- CONSOLE / WEB -->

    <add key ="MI_EnableMail" value ="N"/>
    <add key ="MI_SmtpServer" value ="smtp.mandrillapp.com"/>
    <add key ="MI_PortNumber" value ="587"/>
    <add key ="MI_MailUserID" value ="reports@eshopaid.in"/>
    <add key ="MI_MailPassword" value ="kLKeccu15P76jYxgF75VOg"/>
    <add key ="MI_ToMailIDs" value ="kasan@wondersoftmail.com"/> <!-- Comma separated if more than one Email Ids -->
    <add key ="MI_CCMailIDs" value ="kannan@wondersoft.in"/>  <!-- Comma separated if more than one Email Ids -->

    <add key ="MI_EnableSMS" value ="N"/>
    <add key ="MI_SMSUrl" value ="http://103.250.30.5/SendSMS/sendmsg.php?uname=@SMSUserID&amp;pass=@SMSPassword&amp;send=@SMSSender&amp;dest=@SMSToNumbers&amp;msg=@Message"/>
    <add key ="MI_SMSUserID" value ="wondersoftcrm"/>
    <add key ="MI_SMSPassword" value ="woncrm"/>
    <add key ="MI_SMSSender" value ="Shopad"/>
    <add key ="MI_SMSToNumbers" value ="9381787799"/> <!-- Comma separated if more than one Mobile numbers -->

    <add key="MI_DataPath" value="ImportData"/>    
    <add key="MI_SchemaPath" value="ImportSchema"/>
    <add key="MI_MapPath" value="ImportMapping"/>    
    <add key="MI_InputPath" value="ImportInput"/>    
    <add key="MI_OutputPath" value="ImportOutput"/>
    <add key="MI_LogPath" value="ImportLog"/>    

    <add key="MI_CreateReferenceMaster" value="Y"/>
    <add key="MI_InsertOnly" value="N"/>
    <add key="MI_TransactionScope" value="EACH"/>  <!-- ALL / EACH -->
    <add key ="MI_NotifySuccess" value ="Y"/>
    <add key ="MI_SchemaScope" value ="PUBLIC"/>    <!-- PUBLIC / PRIVATE --> 
    <add key ="MI_FilterSPLChars" value ="Y"/>
    <add key ="MI_AllowedSPLChars" value ="-:;._@#$*!\/"/>   <!--Add special chars except Alphabets and Numeric-->

</appSettings>