Running URT 15.5 Version 2
This can be seen in more current versions of the URT as well.
Starting "UPDATEDLP"."SYS_IMPORT_FULL_01": UPDATEDLP/********@DLPTST dumpfile=sandbox.dmp remap_schema=DLP_USER:UPDATEDLP directory=data_pump_dir logfile=imp_sandbox.log transform=oid:n exclude=STATISTICS
ORA-39346: data loss in character set conversion for object PACKAGE_BODY:"UPDATEDLP"."UPGRADESCHEMA_DATA_MIGRATION"
Upgrade Target Version: 15.5
Readiness Tool Version: 2 and higher
Database Schema Version: 15.0
ORA-39346 and ORA-39383 occurred during the stage 1 import and are related to packages that will be rebuilt by the upgrader anyways.
No further action is required.