500 Servlet Exception

db.auxiliary.DbTagException: Error in resultset tag: java.sql.SQLException:
Column 'sort' in order clause is ambiguous [logging4]
	at db.dbtags.resultSetTag.doStartTag(resultSetTag.java:246)
	at _jsp._metod._books._index2__jsp._jspService(metod/books/index2.jsp:50)
	at com.caucho.jsp.JavaPage.service(JavaPage.java:60)
	at com.caucho.jsp.Page.pageservice(Page.java:570)
	at com.caucho.server.dispatch.PageFilterChain.doFilter(PageFilterChain.java:159)
	at com.caucho.server.cache.CacheFilterChain.doFilter(CacheFilterChain.java:175)
	at com.caucho.server.webapp.WebAppFilterChain.doFilter(WebAppFilterChain.java:163)
	at com.caucho.server.dispatch.ServletInvocation.service(ServletInvocation.java:208)
	at com.caucho.server.hmux.HmuxRequest.handleRequest(HmuxRequest.java:396)
	at com.caucho.server.port.TcpConnection.run(TcpConnection.java:363)
	at com.caucho.util.ThreadPool.runTasks(ThreadPool.java:490)
	at com.caucho.util.ThreadPool.run(ThreadPool.java:423)
	at java.lang.Thread.run(Thread.java:619)