Hi,
That stupid conflict with nimsh is still there and I was not able to find it in installation guide/notes...
Maybe I did not search deeply enough 
The problem in mentioned in the here under note
1622083 - J2EE System fails with "exitcode = -337"
In case it can help anyone reading that thread there is a note on how changing the message port
1623885 - How to change the Message Server port of a Java 7.1 or higher system
You could also change the port used by nimsh
nimsh and SAP (Chris's AIX Blog)
Regards