file not found - how to remove its configuration?
Shut the database down. Start it up again in mount mode:

connect / as sysdba;
startup mount;


Drop the datafile:

ALTER DATABASE DATAFILE '/full/path/of/file.dbf' OFFLINE DROP;


Open the DB:

alter database open;


Drop the tablespace:

DROP TABLESPACE &lt;TS Name&gt; INCLUDING CONTENTS;