web - Strange error in Phoenix logs: running MyApp.Endpoint terminated -

i getting following error in phoenix webapp, developing. simple app few models , page, models create form added in multi-tabbed form.

i getting following error in logs, @ browser's end things working fine. logs not able understand wrong , how debug this.

[error] #pid<0.1603.0> running myapp.endpoint terminated server: localhost:4000 (http) request: / ** (exit) exception raised:     ** (plug.conn.alreadysenterror) response sent         (plug) lib/plug/conn.ex:428: plug.conn.resp/3         (plug) lib/plug/conn.ex:415: plug.conn.send_resp/3         (my_app) web/controllers/personal_info_controller.ex:1: myapp.personalinfocontroller.phoenix_controller_pipeline/2         (my_app) lib/phoenix/router.ex:265: myapp.router.dispatch/2         (my_app) web/router.ex:1: myapp.router.do_call/2         (my_app) lib/my_app/endpoint.ex:1: myapp.endpoint.phoenix_pipeline/1         (my_app) lib/plug/debugger.ex:90: myapp.endpoint."call (overridable 3)"/2         (my_app) lib/phoenix/endpoint/render_errors.ex:34: myapp.endpoint.call/2         (plug) lib/plug/adapters/cowboy/handler.ex:15: plug.adapters.cowboy.handler.upgrade/4         (cowboy) src/cowboy_protocol.erl:442: :cowboy_protocol.execute/4 

you error when duplicate response - happens when have plug send response on error (a user not being logged in example) , response being sent controller action.

without seeing code hard tell problem is. after sending response can use plug.conn.halt/1 prevent error.

e.g.

conn |> send_resp(404, "post not found") |> halt