ORA-00955: name is already used by an existing object

Cause: An attempt was made to create a database object (such as a table, view, cluster, index, or synonym) that already exists. A user's database objects must have distinct names.

Action: Enter a unique name for the database object or modify or drop the existing object so it can be reused.

Cross verify to find the existing object by the given name

SELECT   *   FROM   ALL_OBJECTS where Object_name like '%obj_name%'