ORA-00257: archiver error. Connect internal only, until freed

Cause:

ORA-00257: Error states that there is an issue in the archiver process to write files in the destination. Normally the cause will be in FRA destination size reached the maximum.

Solution:

1) You can increase the db_recovery_file_dest_size to appropriate size.

Eg:
alter system set db_recovery_file_dest_size = 10G scope=both;

2) Alternatively cleanup the old files to get some free spaces by using rman.

i.e
--> delete old archives and backups from FRA
--> set the db_flashback_retention_target to the approriate values , so that you can gain a space over there.

Note :

Before cleanup the files maksure ,
1)  Those files needed for any future actions
2)  You have taken the valid backup

Thats it ....
Keep learning and thing smart to solve all kind of issues in a very simple way...