No handler found for uri [/_sql?sql=select%20*%20from%20distribution%20limit%2010] and method [GET]

Hi,
I installed the sql plugin.
 /usr/share/elasticsearch/bin/plugin -l  
Installed plugins:
    - lang-python
    - head
    - river-csv
    - sql
    - jdbc
    - repository-hdfs

But still the request :
http://161.89.52.213:9200/_sql?sql=select \* from distribution limit 10

gives :
No handler found for uri [/_sql?sql=select%20*%20from%20distribution%20limit%2010] and method [GET]

Regards Hans
