Hi, we are getting the same problem here, please elaborate if you make any progress.
Ok, I have a solution to this error, which works for me.
The general problem is that when JBoss AS is shutdown, the application which contains the custom RepositorySelector implementation is undeployed.
This means that other applications which are undeployed during server shutdown _after_ this, still try to access the custom RepositorySelector through the LogManager if they log during undeployment. This results in a NullPointerException, since the referenced RepositorySelector is already gone.
The NPE is thrown in jboss.Logger.getDelegate(String name) while trying to initialize the LoggerPlugin (a Log4jLoggerPlugin by default), and is caught without printing the stacktrace and printing the "failed to initalize" message instead.
In order to prevent this, the RepositorySelector of LogManager needs to be set to a DefaultRepositorySelector during undeployment of our application.
LogManager.setRepositorySelector(new DefaultRepositorySelector(defaultRepository), guard);
where defaultRepository is the default LoggerRepository and guard is the RootLogger of LogManager which I have saved during the initialization of my custom RepositorySelector