400 Bad Request

how to fix this erron

Hi @bizuapp,

Can you provide more details around the context that you are encountering this error? Can you also indicate the software you are using and the version number (e.g. 3.3.0-13)? You may also want to check on your PHP error logs for errors there. For a general overview of this error, see here: https://developer.mozilla.org/en-US/docs/Web/HTTP/Status/400

PKP team