Ok i've solved the problem. I found the source here:

http://incubator.apache.org/derby/integrate/Readme.html

To download the source you need subversion, s source code version system 
like CVS.

Kai

Susan Cline wrote:
> Hi Kai,
>  
> Starting with version 3.1M6 of Eclipse a class that was used by the 
> Derby UI plug-in is
> no longer available and has been replaced by another Eclipse class.
>  
> 4 files in the Derby plug-in referred to the class 
> org.eclipse.jdt.internal.launching.JavaLocalApplicationLaunchConfigurationDelegate
>  
> the replacement class is:
> org.eclipse.jdt.launching.JavaLaunchDelegate.
>  
> Tony's solution means if you are using the Derby UI plug-in with Eclipse 
> 3.1M6 or higher you'll need to edit these 4 files which are part of the 
> Derby UI plug-in:
>  
> org.apache.derby.ui.launch.SysInfoDerbyLaunchConfigurationDelegate
> org.apache.derby.ui.launch.IJDerbyLaunchConfigurationDelegate
> org.apache.derby.ui.launch.StopDerbyServerLaunchConfigurationDelegate
> org.apache.derby.ui.launch.StartDerbyServerLaunchConfigurationDelegate
>  
> to use the new Eclipse class, org.eclipse.jdt.launching.JavaLaunchDelegate.
>  
> So for instance, looking at the SysInfoDerbyLaunchConfigurationDelegate
> file, the fix is this:
>  
> package org.apache.derby.ui.launch;
>  
> //import 
> org.eclipse.jdt.internal.launching.JavaLocalApplicationLaunchConfigurationDelegate;
> import org.eclipse.jdt.launching.JavaLaunchDelegate
> 
> public class SysInfoDerbyLaunchConfigurationDelegate extends
>   //JavaLocalApplicationLaunchConfigurationDelegate {
>   JavaLaunchDelegate {
> }
>  
> For the other three files make the same change - comment out the 
> deprecated class,
> JavaLocalApplicationLaunchConfigurationDelegate, and use the new one, 
> JavaLaunchDelegate instead.
>  
> Does that make sense?
>  
> Also, either today or tomorrow I'll ask that a couple of web pages be 
> updated to make it clear that the existing 1.0 UI plug-in needs to be 
> used with Eclipse 3.0.x through Eclipse 3.1M5, but
> does not support 3.1M6 or higher, unless you want to manually edit the 
> source for use with
> 3.1M6+.
>  
> Susan
> 
> */Kai-Uwe Beyer <ksi@ksile.de>/* wrote:
> 
>     Hi Susan,
> 
>     i've also this problem with the eclipse version 3.1M7.
>     I don't understand the solution from Tony.
> 
>     Kai
> 
>     Susan Cline wrote:
>      > Thanks for the info Tony.
>      >
>      > Susan
>      >
>      > */Tony Kennedy
>      > /* wrote:
>      >
>      >
>      > The Replacement class is:
>      >
>      > public class IJDerbyLaunchConfigurationDelegate extends
>      > // JavaLocalApplicationLaunchConfigurationDelegate
>      > org.eclipse.jdt.launching.JavaLaunchDelegate
>      >
>      > {
>      >
>      > }
>      >
>      > Tony Kennedy
>      >
>