TypeError - Store can't be referred to

[cavoixanha]

When dump user use gem 'activerecord-session_store' and 'devise' is error method " Marshal.dump(value)", restart server then login, it is working success!
I store model Store by session[:my_store] = current_user.store
How to resolve errors!

Log:

TypeError - Store can't be referred to:
  activerecord-session_store (1.0.0) lib/active_record/session_store.rb:62:in `dump'
  activerecord-session_store (1.0.0) lib/active_record/session_store.rb:13:in `serialize'
  activerecord-session_store (1.0.0) lib/active_record/session_store/session.rb:84:in `serialize_data!'
  activesupport (5.0.1) lib/active_support/callbacks.rb:382:in `block in make_lambda'
  activesupport (5.0.1) lib/active_support/callbacks.rb:169:in `block (2 levels) in halting'
  activesupport (5.0.1) lib/active_support/callbacks.rb:770:in `block (2 levels) in deprecated_false_terminator'
  activesupport (5.0.1) lib/active_support/callbacks.rb:769:in `block in deprecated_false_terminator'
  activesupport (5.0.1) lib/active_support/callbacks.rb:170:in `block in halting'
  activesupport (5.0.1) lib/active_support/callbacks.rb:454:in `block in call'
  activesupport (5.0.1) lib/active_support/callbacks.rb:454:in `call'
  activesupport (5.0.1) lib/active_support/callbacks.rb:101:in `__run_callbacks__'
  activesupport (5.0.1) lib/active_support/callbacks.rb:750:in `_run_save_callbacks'
  activerecord (5.0.1) lib/active_record/callbacks.rb:298:in `create_or_update'
  activerecord (5.0.1) lib/active_record/persistence.rb:125:in `save'
  activerecord (5.0.1) lib/active_record/validations.rb:44:in `save'
  activerecord (5.0.1) lib/active_record/attribute_methods/dirty.rb:22:in `save'
  activerecord (5.0.1) lib/active_record/transactions.rb:319:in `block (2 levels) in save'
  activerecord (5.0.1) lib/active_record/transactions.rb:395:in `block in with_transaction_returning_status'
  activerecord (5.0.1) lib/active_record/connection_adapters/abstract/database_statements.rb:232:in `block in transaction'
  activerecord (5.0.1) lib/active_record/connection_adapters/abstract/transaction.rb:189:in `within_new_transaction'
  activerecord (5.0.1) lib/active_record/connection_adapters/abstract/database_statements.rb:232:in `transaction'
  activerecord (5.0.1) lib/active_record/transactions.rb:211:in `transaction'
  activerecord (5.0.1) lib/active_record/transactions.rb:392:in `with_transaction_returning_status'
  activerecord (5.0.1) lib/active_record/transactions.rb:319:in `block in save'
  activerecord (5.0.1) lib/active_record/transactions.rb:334:in `rollback_active_record_state!'
  activerecord (5.0.1) lib/active_record/transactions.rb:318:in `save'
  activerecord (5.0.1) lib/active_record/suppressor.rb:41:in `save'
  activerecord-session_store (1.0.0) lib/action_dispatch/session/active_record_store.rb:85:in `block in write_session'
  activerecord-session_store (1.0.0) lib/active_record/session_store/extension/logger_silencer.rb:47:in `silence_logger'
  activerecord-session_store (1.0.0) lib/action_dispatch/session/active_record_store.rb:82:in `write_session'
  rack (2.0.1) lib/rack/session/abstract/id.rb:344:in `commit_session'
  rack (2.0.1) lib/rack/session/abstract/id.rb:224:in `context'
  rack (2.0.1) lib/rack/session/abstract/id.rb:216:in `call'
  actionpack (5.0.1) lib/action_dispatch/middleware/cookies.rb:613:in `call'
  activerecord (5.0.1) lib/active_record/migration.rb:553:in `call'
  actionpack (5.0.1) lib/action_dispatch/middleware/callbacks.rb:38:in `block in call'
  activesupport (5.0.1) lib/active_support/callbacks.rb:97:in `__run_callbacks__'
  activesupport (5.0.1) lib/active_support/callbacks.rb:750:in `_run_call_callbacks'
  activesupport (5.0.1) lib/active_support/callbacks.rb:90:in `run_callbacks'
  actionpack (5.0.1) lib/action_dispatch/middleware/callbacks.rb:36:in `call'
  actionpack (5.0.1) lib/action_dispatch/middleware/executor.rb:12:in `call'
  actionpack (5.0.1) lib/action_dispatch/middleware/remote_ip.rb:79:in `call'
  better_errors (2.1.1) lib/better_errors/middleware.rb:84:in `protected_app_call'
  better_errors (2.1.1) lib/better_errors/middleware.rb:79:in `better_errors_call'
  better_errors (2.1.1) lib/better_errors/middleware.rb:57:in `call'
  actionpack (5.0.1) lib/action_dispatch/middleware/debug_exceptions.rb:49:in `call'
  web-console (3.4.0) lib/web_console/middleware.rb:135:in `call_app'
  web-console (3.4.0) lib/web_console/middleware.rb:28:in `block in call'
  web-console (3.4.0) lib/web_console/middleware.rb:18:in `call'
  actionpack (5.0.1) lib/action_dispatch/middleware/show_exceptions.rb:31:in `call'
  railties (5.0.1) lib/rails/rack/logger.rb:36:in `call_app'
  railties (5.0.1) lib/rails/rack/logger.rb:24:in `block in call'
  activesupport (5.0.1) lib/active_support/tagged_logging.rb:69:in `block in tagged'
  activesupport (5.0.1) lib/active_support/tagged_logging.rb:26:in `tagged'
  activesupport (5.0.1) lib/active_support/tagged_logging.rb:69:in `tagged'
  railties (5.0.1) lib/rails/rack/logger.rb:24:in `call'
  sprockets-rails (3.2.0) lib/sprockets/rails/quiet_assets.rb:13:in `call'
  actionpack (5.0.1) lib/action_dispatch/middleware/request_id.rb:24:in `call'
  rack (2.0.1) lib/rack/method_override.rb:22:in `call'
  rack (2.0.1) lib/rack/runtime.rb:22:in `call'
  activesupport (5.0.1) lib/active_support/cache/strategy/local_cache_middleware.rb:28:in `call'
  actionpack (5.0.1) lib/action_dispatch/middleware/executor.rb:12:in `call'
  actionpack (5.0.1) lib/action_dispatch/middleware/static.rb:136:in `call'
  rack (2.0.1) lib/rack/sendfile.rb:111:in `call'
  rack-cors (0.4.1) lib/rack/cors.rb:81:in `call'
  railties (5.0.1) lib/rails/engine.rb:522:in `call'
  puma (3.6.2) lib/puma/configuration.rb:225:in `call'
  puma (3.6.2) lib/puma/server.rb:578:in `handle_request'
  puma (3.6.2) lib/puma/server.rb:415:in `process_client'
  puma (3.6.2) lib/puma/server.rb:275:in `block in run'
  puma (3.6.2) lib/puma/thread_pool.rb:116:in `block in spawn_thread'

Started POST "/__better_errors/7830e9a74c98e08a/variables" for 127.0.0.1 at 2017-07-13 11:13:01 +0700