An ORA-00257 error is reported when importing data to ORACLE through exp

Import data to ORACLE through exp, reported a ORA-00257 error a few days ago to help colleagues installed an ORACLE database server, after loading him with the data exported before the import test, it turns out that the files that only took 7 or 8 minutes in the past were not exported for more than 20 minutes. It seems that it has been suspended. If it is imported to a table, it will not be executed and the program will be suspended. Use PLSQL login, found Exceptions reported, the content is ORA-00257. After analysis, the storage space is allocated ample, and it is not a log space problem. What is it? During the installation process, the Flash Recovery area is set to the ASM storage volume group, and the default value is less than 4 GB. Check space usage: select * from v $ flash_recovery_area_usage; it is found that it is almost exhausted. Therefore, the space is expanded as appropriate based on the actual situation. Statement: alter system set DB_RECOVERY_FILE_DEST_SIZE = 20g.