Earlier Dynamic Data Table is created by using HtmlDataTable object and it is used in xhtml by using attribute binding. I have replaced HtmlDataTable object with HtmlScrollableDataTable object in my java class to fix the header and primary key column in datatable. And in xhtml, I have used following code

<div id="scrollbar"
     style="overflow:scroll;
     min-height:100px;
     max-height: 375px;
     width:1215px;
     border:1px #EEEEEE solid;
     border-top:1px #EEEEEE solid;
     border-bottom:1px #EEEEEE solid;
     border-left: 1px #EEEEEE solid;
     border-right: 1px #EEEEEE solid;">
     <rich:scrollableDataTable binding="#{UserMetadatabean.dynamicDataTable}"
    id="dynamictableList" />
    </div>

With HtmlDataTable the application is running fine but while using the HtmlScrollableDataTable, It is giving the following exception.

com.sun.facelets.FaceletViewHandler handleRenderException SEVERE: Error Rendering View[/pages/metadata.xhtml] java.lang.NullPointerException

Please suggest why this exception is coming and what is the solution. What are the differences between HtmlDataTable and HtmlScrollableDataTable class.