Under Grails1.0.2/Grails1.0.3 environments, I run install-plugin script to install FCK-Editor Plugin, and I got an Exception: ........ Grails Bug: If the plugin wasn't loaded it should be in the failed plugins list, but is not. Please report the issue. java.lang.IllegalArgumentException: Grails Bug: If the plugin wasn't loaded it should be in the fail ed plugins list, but is not. Please report the issue. at org.springframework.util.Assert.notNull(Assert.java:112) at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method) at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:39) at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:25) at java.lang.reflect.Method.invoke(Method.java:585) at org.codehaus.groovy.reflection.CachedMethod.invoke(CachedMethod.java:86) at groovy.lang.MetaMethod.doMethodInvoke(MetaMethod.java:226) at groovy.lang.MetaClassImpl.invokeStaticMethod(MetaClassImpl.java:1094) at groovy.lang.ExpandoMetaClass.invokeStaticMethod(ExpandoMetaClass.java:957) at org.codehaus.groovy.runtime.InvokerHelper.invokeMethod(InvokerHelper.java:748) at org.codehaus.groovy.runtime.ScriptBytecodeAdapter.invokeMethodN(ScriptBytecodeAdapter.jav a:167) at InstallPlugin_groovy$_run_closure3.doCall(InstallPlugin_groovy:176) at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method) ................ It seems a Grails Bug , so I raise this issue