It looks like GWT might be launched without some of its resource jars. This is using a recent GWT 1.5 nightly build. Error: Missing message: compilation_internalError in: org.eclipse.jdt.internal.compiler.messages Error:at com.google.gwt.core.ext.typeinfo.JMethod.getReadableDeclaration(JMethod.java:132) Error:at com.google.gwt.core.ext.typeinfo.JMethod.getReadableDeclaration(JMethod.java:58) Error:at com.google.gwt.user.rebind.rpc.RemoteServiceAsyncValidator.validate(RemoteServiceAsyncValidator.java:200) Error:at com.google.gwt.user.rebind.rpc.ProxyCreator.create(ProxyCreator.java:120) Error:at com.google.gwt.user.rebind.rpc.ServiceInterfaceProxyGenerator.generate(ServiceInterfaceProxyGenerator.java:57) Error:at com.google.gwt.dev.cfg.RuleGenerateWith.realize(RuleGenerateWith.java:43) Error:at com.google.gwt.dev.shell.StandardRebindOracle$Rebinder.tryRebind(StandardRebindOracle.java:118) Error:at com.google.gwt.dev.shell.StandardRebindOracle$Rebinder.rebind(StandardRebindOracle.java:63) Error:at com.google.gwt.dev.shell.StandardRebindOracle.rebind(StandardRebindOracle.java:180) Error:at com.google.gwt.dev.GWTCompiler$DistillerRebindPermutationOracle.getAllPossibleRebindAnswers(GWTCompiler.java:213) Error:at com.google.gwt.dev.jdt.WebModeCompilerFrontEnd.doFindAdditionalTypesUsingRebinds(WebModeCompilerFrontEnd.java:105) Error:at com.google.gwt.dev.jdt.AbstractCompiler$CompilerImpl.process(AbstractCompiler.java:164) Error:at org.eclipse.jdt.internal.compiler.Compiler.compile(Compiler.java:392) Error:at com.google.gwt.dev.jdt.AbstractCompiler$CompilerImpl.compile(AbstractCompiler.java:93) Error:at com.google.gwt.dev.jdt.AbstractCompiler$CompilerImpl.compile(AbstractCompiler.java:194) Error:at com.google.gwt.dev.jdt.AbstractCompiler$CompilerImpl.access$600(AbstractCompiler.java:79) Error:at com.google.gwt.dev.jdt.AbstractCompiler.compile(AbstractCompiler.java:528) Error:at com.google.gwt.dev.jdt.WebModeCompilerFrontEnd.getCompilationUnitDeclarations(WebModeCompilerFrontEnd.java:65) Error:at com.google.gwt.dev.jjs.JavaToJavaScriptCompiler.<init>(JavaToJavaScriptCompiler.java:248) Error:at com.google.gwt.dev.GWTCompiler.distill(GWTCompiler.java:383) Error:at com.google.gwt.dev.GWTCompiler.run(GWTCompiler.java:624) Error:at com.google.gwt.dev.GWTCompiler.run(GWTCompiler.java:614) Error:at com.google.gwt.dev.GWTCompiler.main(GWTCompiler.java:232)