ORA-20001: Latest xml inventory is not loaded into table

Symptoms: As i faced during execute datapatch verbose 19c.
During execution of datapatch or DBMS_QOPATCH following error seen

ERROR:
ORA-20001: Latest xml inventory is not loaded into table
ORA-06512: at "SYS.DBMS_QOPATCH", line 1448
ORA-06512: at "SYS.DBMS_QOPATCH", line 122

Solution: 

1. oraInventory issue
2. Recreate oraceinventory sometime works
3. 19c not using softlink so need to set correct entry into oratabs and run datapatch -verbose

-Because ORACLE_HOME using softlink that's why need to set this parameter for temporary purpose once datapatch done remove this parameter from pfile.

ORA-20001: Latest xml inventory is not loaded into table --->
1.
Startup upgrade
create or replace directory OPATCH_LOG_DIR as '$OH/QOpatch'; ## don't using ORACLE_HOME softlink
create or replace directory OPATCH_SCRIPT_DIR as '$OH/QOpatch';
 
ALTER SYSTEM SET "_disable_directory_link_check" = TRUE SCOPE=SPFILE;
shutdown immediate
startup upgrade
 
 
cd $ORACLE_HOME/OPatch
 
./datapatch -verbose
 
SELECT a.ksppinm "Parameter",b.ksppstvl "Session Value",c.ksppstvl "Instance Value" FROM x$ksppi a, x$ksppcv b, x$ksppsv c WHERE a.indx = b.indx AND a.indx = c.indx AND a.ksppinm LIKE '/_disable_direc%' escape '/';

Ref Doc:
datapatch fails with "ORA-20009:" “ORA-20013: DBMS_QOPATCH ran mostly in non install area” ORACLE_HOME is a SYMBOLIC LINK (Doc ID 2033620.1)
Queryable Patch Inventory - Issues/Solutions for ORA-20001: Latest xml inventory is not loaded into table (Doc ID 1602089.1)