This action will initialize IBM Informix Dynamic Server;
any existing IBM Informix Dynamic Server databases will NOT be accessible -
Do you wish to continue (y/n)? y
No. of listener threads 0 in DBSERVERNAME/DBSERVERALIASES
is in invalid range ( 1<=x<=50 ).
FAILED

WARNING: server initialization failed, or possibly timed out (if -w was used).
Check the message log, online.log, for errors.

Operating System: IBM AIX 5.3.3 ML12
Database: Informix 11.5 FC

can you please post your setting to

NETTYPE
DBSERVERNAME
DBSERVERALIASES

and the corresponding SQLHosts-Entries?

Kind regards
Erik