Hi,
I tried to open my bib file with JabRef, but some strange error occurs, and I receive an error message, which I do not understand and I really do not know how to describe it. See,
" java.lang.NullPointerException
at java.base/java.util.Objects.requireNonNull(Unknown Source)
at org.jabref@5.6.60000/org.jabref.gui.entryeditor.FieldsEditorTab.(Unknown Source)
at org.jabref@5.6.60000/org.jabref.gui.entryeditor.RequiredFieldsTab.(Unknown Source)
at org.jabref@5.6.60000/org.jabref.gui.entryeditor.EntryEditor.createTabs(Unknown Source)
at org.jabref@5.6.60000/org.jabref.gui.entryeditor.EntryEditor.(Unknown Source)
at org.jabref@5.6.60000/org.jabref.gui.LibraryTab.(Unknown Source)
at org.jabref@5.6.60000/org.jabref.gui.LibraryTab$Factory.createLibraryTab(Unknown Source)
at org.jabref@5.6.60000/org.jabref.gui.importer.actions.OpenDatabaseAction.openTheFile(Unknown Source)
at org.jabref@5.6.60000/org.jabref.gui.importer.actions.OpenDatabaseAction.openFiles(Unknown Source)
at org.jabref@5.6.60000/org.jabref.gui.importer.actions.OpenDatabaseAction.openFile(Unknown Source)
at org.jabref@5.6.60000/org.jabref.gui.menus.FileHistoryMenu.openFile(Unknown Source)
at org.jabref@5.6.60000/org.jabref.gui.menus.FileHistoryMenu.lambda$addItem$0(Unknown Source)
at org.jabref.merged.module@5.6.60000/com.sun.javafx.event.CompositeEventHandler.dispatchBubblingEvent(Unknown Source)
at org.jabref.merged.module@5.6.60000/com.sun.javafx.event.EventHandlerManager.dispatchBubblingEvent(Unknown Source)
at org.jabref.merged.module@5.6.60000/com.sun.javafx.event.EventHandlerManager.dispatchBubblingEvent(Unknown Source)
at org.jabref.merged.module@5.6.60000/com.sun.javafx.event.BasicEventDispatcher.dispatchEvent(Unknown Source)
at org.jabref.merged.module@5.6.60000/com.sun.javafx.event.EventDispatchChainImpl.dispatchEvent(Unknown Source)
at org.jabref.merged.module@5.6.60000/com.sun.javafx.event.EventUtil.fireEventImpl(Unknown Source)
at org.jabref.merged.module@5.6.60000/com.sun.javafx.event.EventUtil.fireEvent(Unknown Source)
at org.jabref.merged.module@5.6.60000/javafx.event.Event.fireEvent(Unknown Source)
at org.jabref.merged.module@5.6.60000/javafx.scene.control.MenuItem.fire(Unknown Source)
at org.jabref.merged.module@5.6.60000/com.sun.javafx.scene.control.ContextMenuContent$MenuItemContainer.doSelect(Unknown Source)
at org.jabref.merged.module@5.6.60000/com.sun.javafx.scene.control.ContextMenuContent$MenuItemContainer.lambda$createChildren$12(Unknown Source)
at org.jabref.merged.module@5.6.60000/com.sun.javafx.event.CompositeEventHandler$NormalEventHandlerRecord.handleBubblingEvent(Unknown Source)
at org.jabref.merged.module@5.6.60000/com.sun.javafx.event.CompositeEventHandler.dispatchBubblingEvent(Unknown Source)
at org.jabref.merged.module@5.6.60000/com.sun.javafx.event.EventHandlerManager.dispatchBubblingEvent(Unknown Source)
at org.jabref.merged.module@5.6.60000/com.sun.javafx.event.EventHandlerManager.dispatchBubblingEvent(Unknown Source)
at org.jabref.merged.module@5.6.60000/com.sun.javafx.event.CompositeEventDispatcher.dispatchBubblingEvent(Unknown Source)
at org.jabref.merged.module@5.6.60000/com.sun.javafx.event.BasicEventDispatcher.dispatchEvent(Unknown Source)
at org.jabref.merged.module@5.6.60000/com.sun.javafx.event.EventDispatchChainImpl.dispatchEvent(Unknown Source)
at org.jabref.merged.module@5.6.60000/com.sun.javafx.event.BasicEventDispatcher.dispatchEvent(Unknown Source)
at org.jabref.merged.module@5.6.60000/com.sun.javafx.event.EventDispatchChainImpl.dispatchEvent(Unknown Source)
at org.jabref.merged.module@5.6.60000/com.sun.javafx.event.BasicEventDispatcher.dispatchEvent(Unknown Source)
at org.jabref.merged.module@5.6.60000/com.sun.javafx.event.EventDispatchChainImpl.dispatchEvent(Unknown Source)
at org.jabref.merged.module@5.6.60000/com.sun.javafx.event.BasicEventDispatcher.dispatchEvent(Unknown Source)
at org.jabref.merged.module@5.6.60000/com.sun.javafx.event.EventDispatchChainImpl.dispatchEvent(Unknown Source)
at org.jabref.merged.module@5.6.60000/com.sun.javafx.event.EventUtil.fireEventImpl(Unknown Source)
at org.jabref.merged.module@5.6.60000/com.sun.javafx.event.EventUtil.fireEvent(Unknown Source)
at org.jabref.merged.module@5.6.60000/javafx.event.Event.fireEvent(Unknown Source)
at org.jabref.merged.module@5.6.60000/javafx.scene.Scene$MouseHandler.process(Unknown Source)
at org.jabref.merged.module@5.6.60000/javafx.scene.Scene.processMouseEvent(Unknown Source)
at org.jabref.merged.module@5.6.60000/javafx.scene.Scene$ScenePeerListener.mouseEvent(Unknown Source)
at org.jabref.merged.module@5.6.60000/com.sun.javafx.tk.quantum.GlassViewEventHandler$MouseEventNotification.run(Unknown Source)
at org.jabref.merged.module@5.6.60000/com.sun.javafx.tk.quantum.GlassViewEventHandler$MouseEventNotification.run(Unknown Source)
at java.base/java.security.AccessController.doPrivileged(Unknown Source)
at org.jabref.merged.module@5.6.60000/com.sun.javafx.tk.quantum.GlassViewEventHandler.lambda$handleMouseEvent$2(Unknown Source)
at org.jabref.merged.module@5.6.60000/com.sun.javafx.tk.quantum.QuantumToolkit.runWithoutRenderLock(Unknown Source)
at org.jabref.merged.module@5.6.60000/com.sun.javafx.tk.quantum.GlassViewEventHandler.handleMouseEvent(Unknown Source)
at org.jabref.merged.module@5.6.60000/com.sun.glass.ui.View.handleMouseEvent(Unknown Source)
at org.jabref.merged.module@5.6.60000/com.sun.glass.ui.View.notifyMouse(Unknown Source)
at org.jabref.merged.module@5.6.60000/com.sun.glass.ui.win.WinApplication._runLoop(Native Method)
at org.jabref.merged.module@5.6.60000/com.sun.glass.ui.win.WinApplication.lambda$runLoop$3(Unknown Source)
at java.base/java.lang.Thread.run(Unknown Source)
"
Any ideas?