第一次使用db4o遇到的错误！

我使用objectmanager打开.yap报了以下的错误:
db4o stacktrace>
java.lang.RuntimeException: File format incompatible.
at com.db4o.inside.Exceptions4.throwRuntimeException(Unknown Source)
at com.db4o.inside.Exceptions4.throwRuntimeException(Unknown Source)
at com.db4o.YapFile.readThis(Unknown Source)
at com.db4o.YapRandomAccessFile.open(Unknown Source)
at com.db4o.YapRandomAccessFile.<init>(Unknown Source)
at com.db4o.Sessions.open(Unknown Source)
at com.db4o.Db4o.openFile(Unknown Source)
at com.db4o.browser.model.Db4oFileConnectionSpec.connectInternal(Unknown
Source)
at com.db4o.browser.model.Db4oConnectionSpec.connect(Unknown Source)
at com.db4o.browser.model.Db4oDatabase.reopen(Unknown Source)
at com.db4o.browser.model.Db4oDatabase.open(Unknown Source)
at com.db4o.browser.model.BrowserCore.getDatabase(Unknown Source)
at com.db4o.browser.model.BrowserCore.iterator(Unknown Source)
at com.db4o.browser.gui.controllers.BrowserTabController.internalSetInpu
t(Unknown Source)
at com.db4o.browser.gui.controllers.BrowserTabController.open(Unknown So
urce)
at com.db4o.browser.gui.controllers.BrowserTabController.open(Unknown So
urce)
at com.db4o.browser.gui.standalone.StandaloneBrowser$3.widgetSelected(Un
known Source)
at org.eclipse.swt.widgets.TypedListener.handleEvent(TypedListener.java:
89)
at org.eclipse.swt.widgets.EventTable.sendEvent(EventTable.java:66)
at org.eclipse.swt.widgets.Widget.sendEvent(Widget.java:844)
at org.eclipse.swt.widgets.Display.runDeferredEvents(Display.java:3070)
at org.eclipse.swt.widgets.Display.readAndDispatch(Display.java:2703)
at com.db4o.browser.gui.standalone.SWTProgram.runWithLog(Unknown Source)

at com.db4o.browser.gui.standalone.StandaloneBrowser.main(Unknown Source
)
</db4o stacktrace>
Uncaught exception in SWT event loop
java.lang.IllegalArgumentException: Could not open: F:\work_union\DB4oTest\auto.
yap
at com.db4o.browser.model.Db4oDatabase.reopen(Unknown Source)
at com.db4o.browser.model.Db4oDatabase.open(Unknown Source)
at com.db4o.browser.model.BrowserCore.getDatabase(Unknown Source)
at com.db4o.browser.model.BrowserCore.iterator(Unknown Source)
at com.db4o.browser.gui.controllers.BrowserTabController.internalSetInpu
t(Unknown Source)
at com.db4o.browser.gui.controllers.BrowserTabController.open(Unknown So
urce)
at com.db4o.browser.gui.controllers.BrowserTabController.open(Unknown So
urce)
at com.db4o.browser.gui.standalone.StandaloneBrowser$3.widgetSelected(Un
known Source)
at org.eclipse.swt.widgets.TypedListener.handleEvent(TypedListener.java:
89)
at org.eclipse.swt.widgets.EventTable.sendEvent(EventTable.java:66)
at org.eclipse.swt.widgets.Widget.sendEvent(Widget.java:844)
at org.eclipse.swt.widgets.Display.runDeferredEvents(Display.java:3070)
at org.eclipse.swt.widgets.Display.readAndDispatch(Display.java:2703)
at com.db4o.browser.gui.standalone.SWTProgram.runWithLog(Unknown Source)

at com.db4o.browser.gui.standalone.StandaloneBrowser.main(Unknown Source
)
是什么原因啊？