You have some database corruption, but probably nothing to worry about. The error report is telling you what you should do . . . use REINDEX.
However, before anything you should use pg_dump to get a text backup copy of your entire database.
Then log in to postgres as admin with psql and run the command REINDEX INDEX ir_translation_src_hash_idx
Just Google it for more details : https://www.google.com/search?q=index+contains+unexpected+zero+page+at+block+HINT%3A+Please+REINDEX+it
If you still have problems after that, try pg_restore with the text backup to a new database and see if that one works. I'm confident it will.
So how did you solve this?