ORA-00980: synonym translation is no longer valid

As the name suggests, we can get an idea that while synonym called it is not accessible. There are more than one possibility for this error.

1.) The base table, on which synonym is created, is deleted.
2.)  The entire schema of the base table is dropped and we forget to drop the synonym.
3.) If synonym created on remote database, that is, via dblink. Then please check if dblink is working.

Below query will all the synonyms in the database.

select * from dba_synonyms where table_owner not in ('SYS','SYSTEM');

To avoid looking at the large number of synonyms , you can specify synonym name to look for the table name.

select * from dba_synonyms where table_owner not in ('SYS','SYSTEM') and synonym_name='TEST';