WebSphere Commerce 7 | Storefront Catalog failed to Load | javax.el.ELException: Error reading 'subCategories' | Resolution

Sometimes, you might have merged/added/removed few files from WC Project and from that onwards,
 - Store might be coming up but, it displays none of the catalogs and throws the following exception
 - Entries in STORECAT, STOREDEFCAT might be correct as well
 - If you add catalogId in the URL as one of the parameter, it works
 - If this is the case, few Out of Box files from WC project might be missing
 - I couldn't be able to find which Out of Box WC file was missing
 - But, after replacing with Default WC project again, it started working fine

[9/25/17 16:10:47:213 COT] 0000008c LoggingHelper E /GenericJSPPageError.jsp - Error reading 'subCategories' on type com.ibm.commerce.catalog.beans.CategoryDataBean
                                 javax.el.ELException: Error reading 'subCategories' on type com.ibm.commerce.catalog.beans.CategoryDataBean
    at javax.el.BeanELResolver.getValue(BeanELResolver.java:69)
    at javax.el.CompositeELResolver.getValue(CompositeELResolver.java:143)
    at org.apache.el.parser.AstValue.getValue(AstValue.java:102)
    at org.apache.el.parser.AstEmpty.getValue(AstEmpty.java:29)
    at org.apache.el.parser.AstNot.getValue(AstNot.java:26)
    at org.apache.el.ValueExpressionImpl.getValue(ValueExpressionImpl.java:263)
    at org.apache.jasper.runtime.PageContextImpl.proprietaryEvaluate(PageContextImpl.java:774)
    at com.ibm._jsp._FooterDisplayMenuCategories._jspx_meth_c_if_17(_FooterDisplayMenuCategories.java:7681)
    at com.ibm._jsp._FooterDisplayMenuCategories._jspService(_FooterDisplayMenuCategories.java:1123)
    at com.ibm.ws.jsp.runtime.HttpJspBase.service(HttpJspBase.java:99)
    at javax.servlet.http.HttpServlet.service(HttpServlet.java:831)
    at com.ibm.ws.webcontainer.servlet.ServletWrapper.service(ServletWrapper.java:1667)
    at com.ibm.ws.webcontainer.servlet.ServletWrapper.service(ServletWrapper.java:1602)
    at com.ibm.ws.webcontainer.filter.WebAppFilterChain.doFilter(WebAppFilterChain.java:113)
    at com.ibm.ws.webcontainer.filter.WebAppFilterChain._doFilter(WebAppFilterChain.java:80)
    at com.ibm.ws.webcontainer.filter.WebAppFilterManager.doFilter(WebAppFilterManager.java:908)
    at com.ibm.ws.webcontainer.servlet.ServletWrapper.handleRequest(ServletWrapper.java:939)
    at com.ibm.ws.webcontainer.servlet.ServletWrapper.handleRequest(ServletWrapper.java:507)
    at com.ibm.ws.webcontainer.servlet.ServletWrapperImpl.handleRequest(ServletWrapperImpl.java:181)
    at com.ibm.wsspi.webcontainer.servlet.GenericServletWrapper.handleRequest(GenericServletWrapper.java:121)
    at com.ibm.ws.jsp.webcontainerext.AbstractJSPExtensionServletWrapper.handleRequest(AbstractJSPExtensionServletWrapper.java:259)
    at com.ibm.ws.webcontainer.webapp.WebAppRequestDispatcher.include(WebAppRequestDispatcher.java:732)
    at org.apache.taglibs.standard.tag.common.core.ImportSupport.acquireString(ImportSupport.java:384)
    at org.apache.taglibs.standard.tag.common.core.ImportSupport.doEndTag(ImportSupport.java:220)
    at com.ibm._jsp._CachedHeaderDisplay._jspx_meth_c_import_5(_CachedHeaderDisplay.java:11806)
    at com.ibm._jsp._CachedHeaderDisplay._jspService(_CachedHeaderDisplay.java:1431)
    at com.ibm.ws.jsp.runtime.HttpJspBase.service(HttpJspBase.java:99)
    at javax.servlet.http.HttpServlet.service(HttpServlet.java:831)
    at com.ibm.ws.webcontainer.servlet.ServletWrapper.service(ServletWrapper.java:1667)
    at com.ibm.ws.webcontainer.servlet.ServletWrapper.service(ServletWrapper.java:1602)
    at com.ibm.ws.webcontainer.filter.WebAppFilterChain.doFilter(WebAppFilterChain.java:113)
    at com.ibm.ws.webcontainer.filter.WebAppFilterChain._doFilter(WebAppFilterChain.java:80)
    at com.ibm.ws.webcontainer.filter.WebAppFilterManager.doFilter(WebAppFilterManager.java:908)
    at com.ibm.ws.webcontainer.servlet.ServletWrapper.handleRequest(ServletWrapper.java:939)
    at com.ibm.ws.webcontainer.servlet.ServletWrapper.handleRequest(ServletWrapper.java:507)
    at com.ibm.ws.webcontainer.servlet.ServletWrapperImpl.handleRequest(ServletWrapperImpl.java:181)
    at com.ibm.wsspi.webcontainer.servlet.GenericServletWrapper.handleRequest(GenericServletWrapper.java:121)
    at com.ibm.ws.jsp.webcontainerext.AbstractJSPExtensionServletWrapper.handleRequest(AbstractJSPExtensionServletWrapper.java:259)
    at com.ibm.ws.webcontainer.webapp.WebAppRequestDispatcher.include(WebAppRequestDispatcher.java:732)
    at org.apache.taglibs.standard.tag.common.core.ImportSupport.acquireString(ImportSupport.java:384)
    at org.apache.taglibs.standard.tag.common.core.ImportSupport.doEndTag(ImportSupport.java:220)
    at com.ibm._jsp._GenericError._jspx_meth_c_import_2(_GenericError.java:14380)