[xwiki-users] Error 4001 when I try to edit anything

Hi, I asked this question earlier, but did not get any answers that helped. Whenever I try to edit ANY part of my Xwiki, including the sandbox, I get an error 4001, like this one: Error number 4001 in 4: Error while parsing velocity page /templates/editwysiwygnew.vm Wrapped Exception: Failed to evaluate content with id [/templates/editwysiwygnew.vm]<http://hapkido.myxwiki.org/xwiki/bin/edit/Hapkido+Techniques/Hapkido+Hand+Techniques?section=1> Clicking on this error link gives many lines, like: Error number 4001 in 4: Error while parsing velocity page /templates/editwysiwygnew.vm Wrapped Exception: Failed to evaluate content with id [/templates/editwysiwygnew.vm] com.xpn.xwiki.XWikiException: Error number 4001 in 4: Error while parsing velocity page /templates/editwysiwygnew.vm Wrapped Exception: Failed to evaluate content with id [/templates/editwysiwygnew.vm] at com.xpn.xwiki.render.XWikiVelocityRenderer.evaluate(XWikiVelocityRenderer.java:122) at com.xpn.xwiki.XWiki.evaluateTemplate(XWiki.java:1890) at com.xpn.xwiki.XWiki.parseTemplate(XWiki.java:1828) ... and Wrapped Exception: org.apache.velocity.exception.MethodInvocationException: Invocation of method 'isSourceEditorEnabled' in class org.xwiki.wysiwyg.server.internal.DefaultWysiwygEditorConfiguration threw exception java.lang.NoClassDefFoundError: org/xwiki/gwt/user/client/StringUtils at /templates/macros.vm[line 1963, column 68] at org.apache.velocity.runtime.parser.node.ASTMethod.handleInvocationException(ASTMethod.java:261) at org.apache.velocity.runtime.parser.node.ASTMethod.execute(ASTMethod.java:187) at org.apache.velocity.runtime.parser.node.ASTReference.execute(ASTReference.java:280) ... and Caused by: java.lang.NoClassDefFoundError: org/xwiki/gwt/user/client/StringUtils at org.xwiki.wysiwyg.server.internal.DefaultWysiwygEditorConfiguration.getProperty(DefaultWysiwygEditorConfiguration.java:71) at org.xwiki.wysiwyg.server.internal.DefaultWysiwygEditorConfiguration.isSourceEditorEnabled(DefaultWysiwygEditorConfiguration.java:204) at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method) ... Can anyone tell me what to do? This noob is lost, lost, lost! Thanks, /John