The environment variables you have set for the Oracle installation owner account you use to run the installation can cause issues if they are set to values that conflict with the values needed for installation.

If you have set ORA_CRS_HOME as an environment variable, following instructions from Oracle Support, then unset it before starting an installation or upgrade. You should never use ORA_CRS_HOME as an environment variable except under explicit direction from Oracle Support.

If you have had an existing installation on your system, and you are using the same user account to install this installation, then unset the following environment variables: ORA_CRS_HOME; ORACLE_HOME; ORA_NLS10; TNS_ADMIN; and any other environment variable set for the Oracle installation user that is connected with Oracle software homes.

Also, ensure that the $ORACLE_HOME/bin path is removed from your PATH environment variable.

Unset the environment variable EXTSHM.