我在使用ActionCable进行websocket功能的Rails 5应用程序中出现错误时遇到了令人沮丧的问题。生产日志不间断地发送以下错误：
F, [2017-10-27T12:23:42.289227 #20387] FATAL -- : [adb2f618-9878-46f1-93ab-111ff551f50a] NoMethodError (undefined method `+' for nil:NilClass):
F, [2017-10-27T12:23:42.289287 #20387] FATAL -- : [adb2f618-9878-46f1-93ab-111ff551f50a]
F, [2017-10-27T12:23:42.289353 #20387] FATAL -- : [adb2f618-9878-46f1-93ab-111ff551f50a] websocket-driver (0.6.5) lib/websocket/driver/hybi.rb:11:in `generate_accept'
[adb2f618-9878-46f1-93ab-111ff551f50a] websocket-driver (0.6.5) lib/websocket/driver/hybi.rb:76:in `initialize'
[adb2f618-9878-46f1-93ab-111ff551f50a] websocket-driver (0.6.5) lib/websocket/driver.rb:158:in `new'
[adb2f618-9878-46f1-93ab-111ff551f50a] websocket-driver (0.6.5) lib/websocket/driver.rb:158:in `rack'
[adb2f618-9878-46f1-93ab-111ff551f50a] actioncable (5.0.5) lib/action_cable/connection/client_socket.rb:45:in `initialize'
[adb2f618-9878-46f1-93ab-111ff551f50a] actioncable (5.0.5) lib/action_cable/connection/web_socket.rb:8:in `new'
[adb2f618-9878-46f1-93ab-111ff551f50a] actioncable (5.0.5) lib/action_cable/connection/web_socket.rb:8:in `initialize'
[adb2f618-9878-46f1-93ab-111ff551f50a] actioncable (5.0.5) lib/action_cable/connection/base.rb:60:in `new'
[adb2f618-9878-46f1-93ab-111ff551f50a] actioncable (5.0.5) lib/action_cable/connection/base.rb:60:in `initialize'
[adb2f618-9878-46f1-93ab-111ff551f50a] actioncable (5.0.5) lib/action_cable/server/base.rb:28:in `new'
[adb2f618-9878-46f1-93ab-111ff551f50a] actioncable (5.0.5) lib/action_cable/server/base.rb:28:in `call'
[adb2f618-9878-46f1-93ab-111ff551f50a] actionpack (5.0.5) lib/action_dispatch/routing/mapper.rb:17:in `block in <class:Constraints>'
[adb2f618-9878-46f1-93ab-111ff551f50a] actionpack (5.0.5) lib/action_dispatch/routing/mapper.rb:46:in `serve'
[adb2f618-9878-46f1-93ab-111ff551f50a] actionpack (5.0.5) lib/action_dispatch/journey/router.rb:39:in `block in serve'
[adb2f618-9878-46f1-93ab-111ff551f50a] actionpack (5.0.5) lib/action_dispatch/journey/router.rb:26:in `each'
[adb2f618-9878-46f1-93ab-111ff551f50a] actionpack (5.0.5) lib/action_dispatch/journey/router.rb:26:in `serve'
[adb2f618-9878-46f1-93ab-111ff551f50a] actionpack (5.0.5) lib/action_dispatch/routing/route_set.rb:727:in `call'
[adb2f618-9878-46f1-93ab-111ff551f50a] turnout (2.4.0) lib/rack/turnout.rb:25:in `call'
[adb2f618-9878-46f1-93ab-111ff551f50a] skylight (1.4.3) lib/skylight/probes/middleware.rb:33:in `call'
[adb2f618-9878-46f1-93ab-111ff551f50a] rack-pjax (1.0.0) lib/rack/pjax.rb:12:in `call'
[adb2f618-9878-46f1-93ab-111ff551f50a] skylight (1.4.3) lib/skylight/probes/middleware.rb:33:in `call'
[adb2f618-9878-46f1-93ab-111ff551f50a] oink (0.10.1) lib/oink/middleware.rb:17:in `call'
[adb2f618-9878-46f1-93ab-111ff551f50a] skylight (1.4.3) lib/skylight/probes/middleware.rb:33:in `call'
[adb2f618-9878-46f1-93ab-111ff551f50a] remotipart (1.3.1) lib/remotipart/middleware.rb:32:in `call'
[adb2f618-9878-46f1-93ab-111ff551f50a] skylight (1.4.3) lib/skylight/probes/middleware.rb:33:in `call'
[adb2f618-9878-46f1-93ab-111ff551f50a] rack (2.0.3) lib/rack/etag.rb:25:in `call'
[adb2f618-9878-46f1-93ab-111ff551f50a] skylight (1.4.3) lib/skylight/probes/middleware.rb:33:in `call'
[adb2f618-9878-46f1-93ab-111ff551f50a] rack (2.0.3) lib/rack/conditional_get.rb:25:in `call'
[adb2f618-9878-46f1-93ab-111ff551f50a] skylight (1.4.3) lib/skylight/probes/middleware.rb:33:in `call'
[adb2f618-9878-46f1-93ab-111ff551f50a] rack (2.0.3) lib/rack/head.rb:12:in `call'
[adb2f618-9878-46f1-93ab-111ff551f50a] skylight (1.4.3) lib/skylight/probes/middleware.rb:33:in `call'
[adb2f618-9878-46f1-93ab-111ff551f50a] rack (2.0.3) lib/rack/session/abstract/id.rb:232:in `context'
[adb2f618-9878-46f1-93ab-111ff551f50a] rack (2.0.3) lib/rack/session/abstract/id.rb:226:in `call'
[adb2f618-9878-46f1-93ab-111ff551f50a] skylight (1.4.3) lib/skylight/probes/middleware.rb:33:in `call'
[adb2f618-9878-46f1-93ab-111ff551f50a] actionpack (5.0.5) lib/action_dispatch/middleware/cookies.rb:613:in `call'
[adb2f618-9878-46f1-93ab-111ff551f50a] skylight (1.4.3) lib/skylight/probes/middleware.rb:33:in `call'
[adb2f618-9878-46f1-93ab-111ff551f50a] actionpack (5.0.5) lib/action_dispatch/middleware/callbacks.rb:38:in `block in call'
[adb2f618-9878-46f1-93ab-111ff551f50a] activesupport (5.0.5) lib/active_support/callbacks.rb:97:in `__run_callbacks__'
[adb2f618-9878-46f1-93ab-111ff551f50a] activesupport (5.0.5) lib/active_support/callbacks.rb:750:in `_run_call_callbacks'
[adb2f618-9878-46f1-93ab-111ff551f50a] activesupport (5.0.5) lib/active_support/callbacks.rb:90:in `run_callbacks'
[adb2f618-9878-46f1-93ab-111ff551f50a] actionpack (5.0.5) lib/action_dispatch/middleware/callbacks.rb:36:in `call'
[adb2f618-9878-46f1-93ab-111ff551f50a] skylight (1.4.3) lib/skylight/probes/middleware.rb:33:in `call'
[adb2f618-9878-46f1-93ab-111ff551f50a] actionpack (5.0.5) lib/action_dispatch/middleware/remote_ip.rb:79:in `call'
[adb2f618-9878-46f1-93ab-111ff551f50a] skylight (1.4.3) lib/skylight/probes/middleware.rb:33:in `call'
[adb2f618-9878-46f1-93ab-111ff551f50a] rollbar (2.15.0) lib/rollbar/middleware/rails/rollbar.rb:24:in `block in call'
[adb2f618-9878-46f1-93ab-111ff551f50a] rollbar (2.15.0) lib/rollbar.rb:145:in `scoped'
[adb2f618-9878-46f1-93ab-111ff551f50a] rollbar (2.15.0) lib/rollbar/middleware/rails/rollbar.rb:22:in `call'
[adb2f618-9878-46f1-93ab-111ff551f50a] skylight (1.4.3) lib/skylight/probes/middleware.rb:33:in `call'
[adb2f618-9878-46f1-93ab-111ff551f50a] actionpack (5.0.5) lib/action_dispatch/middleware/debug_exceptions.rb:49:in `call'
[adb2f618-9878-46f1-93ab-111ff551f50a] rollbar (2.15.0) lib/rollbar/middleware/rails/show_exceptions.rb:22:in `call_with_rollbar'
[adb2f618-9878-46f1-93ab-111ff551f50a] skylight (1.4.3) lib/skylight/probes/middleware.rb:33:in `call'
[adb2f618-9878-46f1-93ab-111ff551f50a] actionpack (5.0.5) lib/action_dispatch/middleware/show_exceptions.rb:31:in `call'
[adb2f618-9878-46f1-93ab-111ff551f50a] skylight (1.4.3) lib/skylight/probes/middleware.rb:33:in `call'
[adb2f618-9878-46f1-93ab-111ff551f50a] railties (5.0.5) lib/rails/rack/logger.rb:36:in `call_app'
[adb2f618-9878-46f1-93ab-111ff551f50a] railties (5.0.5) lib/rails/rack/logger.rb:24:in `block in call'
[adb2f618-9878-46f1-93ab-111ff551f50a] activesupport (5.0.5) lib/active_support/tagged_logging.rb:69:in `block in tagged'
[adb2f618-9878-46f1-93ab-111ff551f50a] activesupport (5.0.5) lib/active_support/tagged_logging.rb:26:in `tagged'
[adb2f618-9878-46f1-93ab-111ff551f50a] activesupport (5.0.5) lib/active_support/tagged_logging.rb:69:in `tagged'
[adb2f618-9878-46f1-93ab-111ff551f50a] railties (5.0.5) lib/rails/rack/logger.rb:24:in `call'
[adb2f618-9878-46f1-93ab-111ff551f50a] skylight (1.4.3) lib/skylight/probes/middleware.rb:33:in `call'
[adb2f618-9878-46f1-93ab-111ff551f50a] request_store (1.3.2) lib/request_store/middleware.rb:9:in `call'
[adb2f618-9878-46f1-93ab-111ff551f50a] skylight (1.4.3) lib/skylight/probes/middleware.rb:33:in `call'
[adb2f618-9878-46f1-93ab-111ff551f50a] actionpack (5.0.5) lib/action_dispatch/middleware/request_id.rb:24:in `call'
[adb2f618-9878-46f1-93ab-111ff551f50a] skylight (1.4.3) lib/skylight/probes/middleware.rb:33:in `call'
[adb2f618-9878-46f1-93ab-111ff551f50a] rack (2.0.3) lib/rack/method_override.rb:22:in `call'
[adb2f618-9878-46f1-93ab-111ff551f50a] skylight (1.4.3) lib/skylight/probes/middleware.rb:33:in `call'
[adb2f618-9878-46f1-93ab-111ff551f50a] rack (2.0.3) lib/rack/runtime.rb:22:in `call'
[adb2f618-9878-46f1-93ab-111ff551f50a] skylight (1.4.3) lib/skylight/probes/middleware.rb:33:in `call'
[adb2f618-9878-46f1-93ab-111ff551f50a] activesupport (5.0.5) lib/active_support/cache/strategy/local_cache_middleware.rb:28:in `call'
[adb2f618-9878-46f1-93ab-111ff551f50a] skylight (1.4.3) lib/skylight/probes/middleware.rb:33:in `call'
[adb2f618-9878-46f1-93ab-111ff551f50a] actionpack (5.0.5) lib/action_dispatch/middleware/executor.rb:12:in `call'
[adb2f618-9878-46f1-93ab-111ff551f50a] skylight (1.4.3) lib/skylight/probes/middleware.rb:33:in `call'
[adb2f618-9878-46f1-93ab-111ff551f50a] rack (2.0.3) lib/rack/sendfile.rb:111:in `call'
[adb2f618-9878-46f1-93ab-111ff551f50a] skylight (1.4.3) lib/skylight/probes/middleware.rb:33:in `call'
[adb2f618-9878-46f1-93ab-111ff551f50a] skylight (1.4.3) lib/skylight/middleware.rb:78:in `call'
[adb2f618-9878-46f1-93ab-111ff551f50a] railties (5.0.5) lib/rails/engine.rb:522:in `call'
[adb2f618-9878-46f1-93ab-111ff551f50a] puma (3.10.0) lib/puma/configuration.rb:225:in `call'
[adb2f618-9878-46f1-93ab-111ff551f50a] puma (3.10.0) lib/puma/server.rb:605:in `handle_request'
[adb2f618-9878-46f1-93ab-111ff551f50a] puma (3.10.0) lib/puma/server.rb:437:in `process_client'
[adb2f618-9878-46f1-93ab-111ff551f50a] puma (3.10.0) lib/puma/server.rb:301:in `block in run'
[adb2f618-9878-46f1-93ab-111ff551f50a] puma (3.10.0) lib/puma/thread_pool.rb:120:in `block in spawn_thread'
[adb2f618-9878-46f1-93ab-111ff551f50a] logging (2.2.2) lib/logging/diagnostic_context.rb:474:in `block in create_with_logging_context'
在对引用的库源进行了一些挖掘之后，似乎应该是来自客户端的websocket请求的头部的Sec-Websocket-Key为空。我想知道这是一个过期的会话仍然试图查询套接字的某种问题。
非常感谢任何见解。谢谢！