sqlldr not working on Linux/Unix/Solaris or Windows

When we face below message when try to run "sqlldr" on windows system

Message 2100 not found; No message file for product=RDBMS, facility=UL
Message 2100 not found; No message file for product=RDBMS, facility=UL

then please check metalink note: 1081848.6

When we face below message on *nix platform during running "sqlldr"

Message 2100 not found; No message file for product=RDBMS, facility=UL
Message 2100 not found; No message file for product=RDBMS, facility=UL


Possible Reasons:

1. Oracle Enviourment Variable is not set-up properly

1. ORACLE_HOME, 2. ORACLE_SID, 3. PATH

2. Linux User don't have sufficient permission on $ORACLE_HOME/bin folder
3. Message 2100 not found:

$ oerr sql 2100
02100, 00000, "Out of memory (i.e., could not allocate)"
// *Cause: SQLLIB was unable to allocate enough memory to execute
// the program.
// *Action: Allocate more memory to the user session, then rerun the
program.
// If the error persists, call customer support for
assistance.
$ oerr ul 2100
2100, 0, "%s"

4. Linux user is not a member of DBA group
5. Faulty Oracle Installation