I am trying to rename a user from upper case to lower case using rename users pl

...com.appiancorp.suiteapi.common.exceptions.DuplicateNameException: Duplicate names are not permitted
2015-03-03 19:11:20,684 GMT INFO [stdout] (default-threads - 14) at sun.reflect.NativeConstructorAccessorImpl.newInstance0(Native Method)
2015-03-03 19:11:20,684 GMT INFO [stdout] (default-threads - 14) at sun.reflect.NativeConstructorAccessorImpl.newInstance(NativeConstructorAccessorImpl.java:57)
2015-03-03 19:11:20,684 GMT INFO [stdout] (default-threads - 14) at sun.reflect.DelegatingConstructorAccessorImpl.newInstance(DelegatingConstructorAccessorImpl.java:45)
2015-03-03 19:11:20,684 GMT INFO [stdout] (default-threads - 14) at java.lang.reflect.Constructor.newInstance(Constructor.java:526)
2015-03-03 19:11:20,684 GMT INFO [stdout] (default-threads - 14) at com.appiancorp.kougar.mapper.Mapper.prepareThrowable(Mapper.java:139)
2015-03-03 19:11:20,684 GMT INFO [stdout] (default-threads - 14) at com.appiancorp.kougar.mapper.Mapper.request(Mapper.java:88)
20...

...15-03-03 19:11:20,684 GMT INFO [stdout] (default-threads - 14) at com.appiancorp.kougar.services.KougarServiceInvocationHandler$KInvocationHandler.invoke(KougarServiceInvocationHandler.java:179)
2015-03-03 19:11:20,684 GMT INFO [stdout] (default-threads - 14) at com.appiancorp.kougar.services.KougarServiceInvocationHandler$KougarMethodInvocation.proceed(KougarServiceInvocationHandler.java:271)
2015-03-03 19:11:20,684 GMT INFO [stdout] (default-threads - 14) at com.appiancorp.security.authz.AuthorizationMethodInterceptor.invoke(AuthorizationMethodInterceptor.java:54)
2015-03-03 19:11:20,684 GMT INFO [stdout] (default-threads - 14) at com.appiancorp.kougar.services.KougarServiceInvocationHandler.invoke(KougarServiceInvocationHandler.java:308)
2015-03-03 19:11:20,684 GMT INFO [stdout] (default-threads - 14) at com.sun.proxy.$Proxy131.updateUsernames(Unknown Source)
2015-03-03 19:11:20,684 GMT INFO [stdout] (default-threads - 14) at com.appiancorp.a2.plugins...

... .userServices.RenameUserService.updateUsernames(RenameUserService.java:43)
2015-03-03 19:11:20,684 GMT INFO [stdout] (default-threads - 14) ... 67 more

Have you tried renaming the user to something different than just changing the case and then renaming to the value you want. That might get rid of the duplicate user error. I've not used the plugin before though so it's just a thought.

Agree with the above solution. This post describes the step-by-step process -
forum.appian.com/.../e-128824