Fast for SharePoint 2010 throws the following while trying to crawl the List Item

While trying to crawl the SharePoint contents, Fast for SharePoint 2010 throws the following error:

Could not Add Query Info to the queue:System.ArgumentOutOfRangeException: The value must be at most 256 characters long. Parameter name: info.DidYouMean at Microsoft.Office.Server.Search.DataVerification.ThrowIfInvalidString(String s, String parameterName, StringRestrictions restrictions, Int32 maxLength) at Microsoft.Office.Server.Search.Query.QueryLogQueue.AddQueryInfoHelper(QueryInfo info) at Microsoft.Office.Server.Search.Query.QueryLogQueue.AddQueryInfo(QueryInfo info)

what does it mean?