I'm having the same problem! And it's only started happening after I installed 2.1 for OSX. Now, even if I run my old 17c in Classic, it won't work. Neither one works! Why haven't the programmers helped us yet? I see other people have posted similar distress. Following is my error report from the crash of 17c in Classic:

java.lang.NullPointerException
at com.limegroup.gnutella.SettingsManager.addDirector y(Compiled Code)
at com.limegroup.gnutella.SettingsManager.validateFil e(Compiled Code)
at com.limegroup.gnutella.SettingsManager.initialize( SettingsManager.java:375)
at com.limegroup.gnutella.SettingsManager.<init>(Sett ingsManager.java:360)
at
at com.limegroup.gnutella.gui.ResourceManager.<init>( ResourceManager.java:53)
at
at com.limegroup.gnutella.gui.Initializer.initialize( Initializer.java:52)
at com.limegroup.gnutella.gui.Main.main(Main.java:16)
at com.zerog.lax.LAX.launch(Compiled Code)
at com.zerog.lax.LAX.main([DashoPro-V1.2-120198])
at com.apple.mrj.JManager.JMStaticMethodDispatcher.ru n(JMAWTContextImpl.java)
at java.lang.Thread.run(Thread.java)