unexpected error during fresh start by docs

[nkr-404-NotFound]

010_Intro/35_Tutorial_Aggregations.asciidoc

here when excute the example:

{
"aggs": {
"all_interests": {
"terms": { "field": "interests" }
}
}
}
'

elastic search returned :
{
"error" : {
"root_cause" : [
{
"type" : "illegal_argument_exception",
"reason" : "Fielddata is disabled on text fields by default. Set fielddata=true on [interests] in order to load fielddata in memory by uninverting the inverted index. Note that this can however use significant memory. Alternatively use a keyword field instead."
}
],
"type" : "search_phase_execution_exception",
"reason" : "all shards failed",
"phase" : "query",
"grouped" : true,
"failed_shards" : [
{
"shard" : 0,
"index" : "megacorp",
"node" : "3uJClDOmRmKlDjKWYMsYRQ",
"reason" : {
"type" : "illegal_argument_exception",
"reason" : "Fielddata is disabled on text fields by default. Set fielddata=true on [interests] in order to load fielddata in memory by uninverting the inverted index. Note that this can however use significant memory. Alternatively use a keyword field instead."
}
}
]
},
"status" : 400
}

i think it is caused by some version change in default settings , so the doc needs improvement , add corresponding settings before this chapter :)