ORA-01260: warning: END BACKUP succeeded but some files found not to be in backup mode

When we receive the following error ? How to find to fix it or to ignore?

SQL> alter database end backup;
alter database end backup
*
ERROR at line 1:
ORA-01260: warning: END BACKUP succeeded but some files found not to be in backup mode

Situation : While trying to end the hot backup , will receive the above error.

Action:

Verify the file status from v$backup, If still any file found ACTIVE then retry the end backup or If found INACTIVE then not an issue.

SQL> select file#,status from v$backup;

FILE# STATUS
---------- ------------------
1 NOT ACTIVE
2 NOT ACTIVE
3 NOT ACTIVE
4 NOT ACTIVE
5 NOT ACTIVE
7 NOT ACTIVE

So found NOT ACTIVE , so we can ignore the error. This could be due to some waits in the database caused slow to perform end backup.