I thought it was a character set conversion problem when using the original import (imp) to import a dump file, so I tried to change correct character set for later import. But IMP-00038 is still there.
D:\app\oracle\admin\ORCL\dpdump>imp \"/ as sysdba\" FROMUSER=ERPAPP IGNORE=y FILE=exp_demo.dmp LOG=imp_demo_meta_20200902-1.log
Import: Release 126.96.36.199.0 - Production on Thu Sep 1 21:45:32 2020
Copyright (c) 1982, 2014, Oracle and/or its affiliates. All rights reserved.
Connected to: Oracle Database 12c Enterprise Edition Release 188.8.131.52.0 - 64bit
Production With the Partitioning, OLAP, Advanced Analytics and Real Application Testing options
IMP-00038: Could not convert to environment character set's handle
IMP-00000: Import terminated unsuccessfully