Oracle Restart:rootupgrade.sh failed with error PROTL-6 and PROCL-59 (Doc ID 2759560.1)

Problem Summary

rootupgrade.sh failed with following error.

cat root_<HOSTNAME>_2021-03-10_19-20-47-282911269.log
Performing root user operation.

The following environment variables are set as:
   ORACLE_OWNER= oracle
   ORACLE_HOME=  /<GRID_HOME>
  Copying dbhome to /usr/local/bin ...
  Copying oraenv to /usr/local/bin ...
  Copying coraenv to /usr/local/bin ...

Entries will be added to the /etc/oratab file as needed by
Database Configuration Assistant when a database is created
Finished running generic part of root script.
Now product-specific root actions will be performed.
Using configuration parameter file: <GRID_HOME>/crs/install/crsconfig_params
The log of current session can be found at:
 /oracle/crsdata/<HOSTNAME>/crsconfig/roothas_2021-03-10_07-20-47PM.log
2021/03/10 19:20:49 CLSRSC-595: Executing upgrade step 1 of 12: 'UpgPrechecks'.
2021/03/10 19:20:52 CLSRSC-363: User ignored prerequisites during installation
2021/03/10 19:20:52 CLSRSC-595: Executing upgrade step 2 of 12: 'GetOldConfig'.
2021/03/10 19:20:55 CLSRSC-595: Executing upgrade step 3 of 12: 'GenSiteGUIDs'.
2021/03/10 19:20:55 CLSRSC-595: Executing upgrade step 4 of 12: 'SetupOSD'.
2021/03/10 19:20:55 CLSRSC-595: Executing upgrade step 5 of 12: 'PreUpgrade'.
2021/03/10 19:21:17 CLSRSC-595: Executing upgrade step 6 of 12: 'UpgradeAFD'.
2021/03/10 19:21:17 CLSRSC-595: Executing upgrade step 7 of 12: 'UpgradeOLR'.
PROTL-6: The specified Oracle Local Registry import file '/oracle/crsdata/<HOSTNAME>/olr/OLRUPGRADEFILE' is not accessible.
PROCL-59: The specified Oracle Local Registry export/import file location is not accessible.
2021/03/10 19:21:19 CLSRSC-169: Failed to create or upgrade OLR
Died at <GRID_HOME>/crs/install/oraolr.pm line 562.

 Upgrade grid from 18c to 19c