LsInventorySession failed: OracleHomeInventory gets null oracleHomeInfo

 opatch lsinventory

Oracle Interim Patch Installer version 11.1.0.9.9
Copyright (c) 2012, Oracle Corporation.  All rights reserved.

List of Homes on this system:

Inventory load failed... OPatch cannot load inventory for the given Oracle Home.
Possible causes are:
   Oracle Home dir. path does not exist in Central Inventory
   Oracle Home is a symbolic link
   Oracle Home inventory is corrupted
LsInventorySession failed: OracleHomeInventory gets null oracleHomeInfo

OPatch failed with error code 73

Solution:
i was missing following files under /home/oracle/oraInventory after copying these files. OPATCH worked for me.

ContentsXML
createCentralInventory.sh
oui