Symptoms

When attempting to edit the details of User Directory established to connect to Crowd, a system error page is thrown in the browser and Confluence crashes.

The following appears in the atlassian-confluence.log:

2012-04-03 11:49:41,643 ERROR [http-7020-4] [sf.hibernate.util.JDBCExceptionReporter] logExceptions ERROR: duplicate key value violates unique constraint "cwd_directory_lower_directory_name_key"
 -- referer: http://xxx.xxx.xxx.xxx/plugins/servlet/embedded-crowd/configure/crowd/ | url: /plugins/servlet/embedded-crowd/configure/crowd/ | userName: xxxxxxx

Resolution

1. Delete the entry for the crowd connection in Confluence Admin>>User Directories

2. Recreate the entry for the crowd connection (Crowd User Directory)