opatch error: OracleHomeInventory gets null oracleHomeInfo

Opatch raised the following error:

ApplySession failed: ApplySession failed to prepare the system. OracleHomeInventory gets null oracleHomeInfo
System intact, OPatch will not attempt to restore the system

OPatch failed with error code 73

In order to find root cause;

export OPATCH_DEBUG=TRUE

then run "opatch apply" again. Following lines give more information.

Home name= OUIHome1, Location= "/u01/app/oracle/product/10.2.0"
Home name= OraDb11g_home1, Location= "/u01/app/oracle/11g/version/11107"
Home name= OraDb11g_examples, Location= "/u01/app/oracle/11gExamples"
OracleHomeInventory::createInventoryObj() construction done
OracleHomeInventory::load()
OPatchSession cannot load inventory for the given Oracle Home /u01/app/oracle/product/10.2.0.4. Possible causes are:
No read or write permission to ORACLE_HOME/.patch_storage
Central Inventory is locked by another OUI instance
No read permission to Central Inventory
The lock file exists in ORACLE_HOME/.patch_storage
The Oracle Home does not exist in Central Inventory

You can see that opatch runs under /u01/app/oracle/product/10.2.0.4 but inventory doesn't show this path as an Oracle Home. There is something wrong with the inventory data.

To fix the problem, i edited the following file in order to correct "OUIHome1" as /u01/app/oracle/product/10.2.0.4

$ORACLE_BASE/oraInventory/ContentsXML/inventory.xml

format must be like: