I have recently installed Oracle 11g r2 on a RedHat 5.5 server. now I can't get the sqlplus to open or start, it just gives the error:
Eror 6 initializing SQL*Plus
SP2-0667:Message file sp1<lang>.msb not found
SP2-0750: You may need to set ORACLE_HOME to your Oracle software directory
I have set and reset the ORACLE_HOME, ORACLE_BASE AND ORACLE_SID. I've exported them and can run the 'echo' command to see that they are set correctly, but still get the same error.