undefined field: spell

I am getting undefined field: \"spell\ response message .

While request URL is

GET /solr/testing/select?start=0&rows=0&&facet=true&facet.field=spell&facet.field=spell&facet.limit=25&facet.mincount=1&facet.prefix=f&spellcheck.q=&spellcheck=true&qf=content%5E40&qf=label%5E5.0&qf=tags_h4_h5_h6%5E2.0&qf=tags_inline%5E1.0&qf=tos_content_extra%5E0.1&qf=tos_name%5E3.0&qf=ts_comments%5E20&wt=json&json.nl=map

which is made by solr auto complete module.

Please suggest me where i ma wrong.