Failed to launch Splunk with error "Validating databases (splunkd validatedb) failed with code '1'."

Recently I moved my previous Splunk db from my old laptop to the new one.  There is an error "Validating databases (splunkd validatedb) failed with code '1’.”” When I tried to launch the Splunk.  After did some googling, I found it was caused by file locked.  The solution is to append the following configuration option to  $SPLUNK_HOME/etc/splunk-launch.conf:

#########################

OPTIMISTIC_ABOUT_FILE_LOCKING = 1