vbulletin options
 

i am trying to edit my forum page and currently cant enter to vbulletin options > search type

everytime time i click this, it appear this message

Quote:
Your forum is currently using the Fulltext search engine.

If you wish to revert to the vBulletin search engine, please continue. You can leave the Fulltext indexes in place if you expect to return to the Fulltext search in the near future. Leaving them in place will cause added load on your system in the interim. Remove Fulltext Indexes
can someone help me here!? sorry for the noob question!