Report Server (MSSQLSERVER) cannot load the SQLPDW extension

Hi

We are getting below errors in event viewer.

Report Server (MSSQLSERVER) cannot load the SQLPDW extension

Report Server (MSSQLSERVER) cannot load the TERADATA extension

We have commented SQLPDW & TERADATA extension in rsreportserver config file as below

<!--Extension Name="SQLPDW" Type="Microsoft.ReportingServices.DataExtensions.SqlDwConnectionWrapper,Microsoft.ReportingServices.DataExtensions"/—>

<!--Extension Name="SQLPDW" Type="Microsoft.ReportingServices.SemanticQueryEngine.Sql.MSSQLADW.MSSqlAdwSQCommand,Microsoft.ReportingServices.SemanticQueryEngine">
    <Configuration>
        <EnableMathOpCasting>False</EnableMathOpCasting>
    </Configuration>
</Extension-->

<!--Extension Name="TERADATA" Type="Microsoft.ReportingServices.DataExtensions.TeradataConnectionWrapper,Microsoft.ReportingServices.DataExtensions"/—>

<!--Extension Name="TERADATA" Type="Microsoft.ReportingServices.SemanticQueryEngine.Sql.Teradata.TdSqlSQCommand,Microsoft.ReportingServices.SemanticQueryEngine">
    <Configuration>
        <EnableMathOpCasting>True</EnableMathOpCasting>
        <ReplaceFunctionName>oREPLACE</ReplaceFunctionName>
    </Configuration>
</Extension—>

<!--Extension Name="TERADATA" Type="Microsoft.ReportingServices.SemanticQueryEngine.Sql.Teradata.TdSqlModelGenerator,Microsoft.ReportingServices.SemanticQueryEngine"/-->

After above changes we are not able to restart SSRS services. In event viewer the below message is showing. Please suggest on this issue. 

Service cannot be started. System.Exception: Default appdomain failed to initialize.
   at Microsoft.ReportingServices.Library.ServiceAppDomainController.Start()
   at Microsoft.ReportingServices.Library.ReportService.OnStart(String[] args)
   at System.ServiceProcess.ServiceBase.ServiceQueuedMainCallback(Object state)