OPatch Error after copying Oracle Home : Inventory load failed... OPatch cannot load inventory for the given Oracle Home.

In order to save time, I copied Oracle Database Home from one server to another including the inventory. When I tried to do a 'lsinventory' I got the following error:

$opatch lsinventory -invPtrLoc /r01/app/oracle/oradb/oraInventory/oraInst.loc

Oracle Interim Patch Installer version 12.1.0.1.6
Copyright (c) 2015, Oracle Corporation.  All rights reserved.


Oracle Home       : /r01/app/oracle/oradb/12.1.0
Central Inventory : /r01/app/oracle/oradb/oraInventory
   from           : /r01/app/oracle/oradb/oraInventory/oraInst.loc
OPatch version    : 12.1.0.1.6
OUI version       : 12.1.0.2.0
Log file location : /r01/app/oracle/oradb/12.1.0/cfgtoollogs/opatch/opatch2015-06-02_10-31-39AM_1.log

List of Homes on this system:

  Home name= OraDB12Home1, Location= "/u01/app/oracle/oradb/12.1.0"
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:

Go to the Inventory location (in my case /r01/app/oracle/oradb/oraInventory/ContentsXML) and search for inventory.xml. Replace

HOME NAME="OraDB12Home1" LOC="/u01/app/oracle/oradb/12.1.0" TYPE="O" IDX="1"
with
HOME NAME="OraDB12Home1" LOC="/r01/app/oracle/oradb/12.1.0" TYPE="O" IDX="1" 

in the inventory.xml and save it.