java.lang.NullPointerException when leaving a mandatory fiel

I have deleted all the triggers, expression/formula fields in the grid control. I have also disabled all the scripts. I have added one mandatory field (for testing purposes) in the grid-control. If i leave this field empty, the systems turns a java.lang.NullPointerException error. I have this problem on my own test private environment. After loading the same application in the hosted environment, everything works fine. It shoudl be something simple. Any idea? java.lang.NullPointerException at com.rb.core.data.definition.DataObjectDef.canEditRecord(DataObjectDef.java:1349) at com.rb.core.ui.web.cell.GridControl._x10(GridControl.java:475) at com.rb.core.ui.web.PageSection._x10(PageSection.java:477) at com.rb.core.ui.web.WebPage.appendTabbedRuntimeHTML(WebPage.java:1046) at com.rb.core.ui.web.WebPage.getRuntimeHTML(WebPage.java:807) at com.rb.core.logics.servlet.MainServlet.doGet(MainServlet.java:98) at javax.servlet.http.HttpServlet.serv