Error: "exec(): 0509-036 Cannot load program ./qexecd because of the following errors:" during (4213504)

Error received during Quest Server Agent Upgrade:

"exec(): 0509-036 Cannot load program ./qexecd because of the following errors:
0509-150 Dependent module libclntsh.a(shr.o) could not be loaded.
0509-022 Cannot load module libclntsh.a(shr.o).
0509-026 System error: A file or directory in the path name does not exist."

or

When stop/starting the QSA after the upgrade:
./QSAStop.sh
exec(): 0509-036 Cannot load program ./qexecd because of the following errors:
0509-150 Dependent module /oracle/client/10x_64/instanctclient/libclntsh.a(shr.o) could not be loaded.
0509-103 The module has an invalid magic number.
Completed

./QSAStart.sh
exec(): 0509-036 Cannot load program ./qexecd because of the following errors:
0509-150 Dependent module /oracle/client/10x_64/instanctclient/libclntsh.a(shr.o) could not be loaded.
0509-103 The module has an invalid magic number.
Failed QSA-20316 Couldn't start daemon

CAUSE 1

Conflict with old installation configuration.

CAUSE 2

Library paths are not defined on the installing UNIX user or is pointing to a 64-bit library instead of a 32-bit path.

WORKAROUND 1

1. Connect to the database with SQL*Plus, and run the following:

Delete quest_com_products where product_id = '61';
Commit;

2. Delete the old QSA installation directory.  Run the following to determine the location:

select value from QUEST_EXEC_PARAMETER where name='INSTALL_DIR';

3.  Reinstall the Quest Server Agent.

WORKAROUND 2

Prior to installation, check if the LD_LIBRARY_PATH and/or SHLIB_PATH environment variables has the $ORACLE_HOME/lib entry for the installing UNIX user:
echo $LD_LIBRARY_PATH
echo $SHLIB_PATH

If not, then export the variables to contain $ORACLE_HOME/lib or the folder where libclntsh.a is located.  Note that there are some versions of the QSA that is not compatible with a 64-bit Oracle client.  Please refer to the Space Manager version's Release Notes for more details on the supported versions.  If the version is found not to be compatible with 64-bit, then the LD_LIBRARY_PATH/SHLIB_PATH should point to the 32-bit libraries (e.g. $ORACLE_HOME/lib32).