Index cannot be dropped when it is clearly MySql?

Question

MySQL

Request:
DROP INDEX `title` ON `slc_folders`;
Error:

Невозможно удалить (DROP) 'title'. Убедитесь что столбец/ключ действительно существует

The index is clearly there, it stands, before that I set it with the CREATE INDEX `title` command .
Why can't I drop it now?

Answer 1

Maybe there is, maybe not - I would look at what to swear.