Installation process errors out with "Error: Add spadmin group (groupadd) failed. error 9" (4330699)

When installing Shareplex, the installation process aborts with the following:

bash-3.00# ./SharePlex_Oracle-5.3.0.63-Linux-x86-Oracle10.run
Creating directory SharePlex_Oracle-5.3.0.63-Linux-x86-Oracle10.run.tmp
Verifying archive integrity... All good.
Uncompressing SharePlex_Oracle-5.3.0.63-Linux-x86-Oracle10-Self_Extra Tar File

Checking usage of a nameserver for users and groups; Enter your nameserver or none [NIS/NISPLUS/none]: none

Installing Product(s): SPLEX-ORACLE

Please specify an existing user who has read privileges to the Oracle redo logs and will own the SharePlex product and variable-data directories. This user will be a SharePlex Administrator and placed in the SharePlex admin group [oracle]:
Adding groups to the system.
Error: Add spadmin group (groupadd) failed. error 9