I'm trying to use Zabbix 2.0 rc2. Cannot create discovery action that attaches a template to a discovered host.

My API JSON request:
[PHP]{
"params" : {
"recovery_msg" : "0",
"status" : "0",
"r_shortdata" : "",
"name" : "???????????????",
"operations" : [

{ "esc_step_from" : "1", "esc_period" : "0", "optemplate" : [ "10016" ], "operationtype" : "6", "evaltype" : "0", "esc_step_to" : "1", "opconditions" : [] }

],
"esc_period" : "0",
"def_shortdata" : "",
"evaltype" : "0",
"r_longdata" : "",
"eventsource" : "1",
"actionid" : "5",
"def_longdata" : "",
"conditions" : [

{ "operator" : "0", "value" : "4", "conditiontype" : "18" }

]
},
"auth" : "0e907e5d00862cb87912c63d294bca05",
"jsonrpc" : "2.0",
"method" : "action.update",
"id" : 178
}[/PHP]

I get the following error:
[PHP]In create_or_update_discovery_action: Error:

{"data":"JSON-rpc error generation failed. No such error \"\".","message":"System error.","code":-32400}

[/PHP]