標準編集モード（旧簡易モード）でテーブルの編集画面において、
いったんある型を関連データ型に設定した後、他のデータ型に変更するとアプリケーションエラーが発生する。
発生するエラーは以下の通り。画面上では、Javascriptのダイアログで、undefinedと表示される。

java.lang.NullPointerException
at org.seasar.tuigwaa.controller.EntityForm.removeRow(EntityForm.java:244)
at org.seasar.tuigwaa.util.ajax.AbstractRowSetForm.removeRow(AbstractRowSetForm.java:208)
at org.seasar.tuigwaa.util.ajax.AbstractRowSetForm.replaceRow(AbstractRowSetForm.java:198)
at org.seasar.tuigwaa.util.ajax.AbstractRowSetForm.replaceRowByAjax(AbstractRowSetForm.java:125)
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:39)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:25)
at java.lang.reflect.Method.invoke(Method.java:585)
at com.metaparadigm.jsonrpc.JSONRPCBridge.call(JSONRPCBridge.java:934)
at com.metaparadigm.jsonrpc.JSONRPCServlet.service(JSONRPCServlet.java:166)
at javax.servlet.http.HttpServlet.service(HttpServlet.java:802)
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:252)
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:173)
at org.seasar.tuigwaa.util.filter.ForwardFilter.doFilter(ForwardFilter.java:83)
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:202)
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:173)
at org.seasar.struts.filter.S2StrutsFilter.doFilter(S2StrutsFilter.java:45)
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:202)
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:173)
at org.seasar.framework.container.filter.S2ContainerFilter.doFilter(S2ContainerFilter.java:60)
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:202)
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:173)
at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:213)
at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:178)
at org.apache.catalina.authenticator.AuthenticatorBase.invoke(AuthenticatorBase.java:432)
at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:126)
at org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:105)
at org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:107)
at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:148)
at org.apache.coyote.http11.Http11Processor.process(Http11Processor.java:869)
at org.apache.coyote.http11.Http11BaseProtocol$Http11ConnectionHandler.processConnection(Http11BaseProtocol.java:664)
at org.apache.tomcat.util.net.PoolTcpEndpoint.processSocket(PoolTcpEndpoint.java:527)
at org.apache.tomcat.util.net.LeaderFollowerWorkerThread.runIt(LeaderFollowerWorkerThread.java:80)
at org.apache.tomcat.util.threads.ThreadPool$ControlRunnable.run(ThreadPool.java:684)
at java.lang.Thread.run(Thread.java:595)