There are all things:
[351] [2020/02/25 15:56:28.054] F: JSON::ParserError (A JSON text must at least contain two octets!):
vendor/ruby/1.9.1/gems/json-1.8.0/lib/json/common.rb:155:in `initialize'
vendor/ruby/1.9.1/gems/json-1.8.0/lib/json/common.rb:155:in `new'
vendor/ruby/1.9.1/gems/json-1.8.0/lib/json/common.rb:155:in `parse'
config/initializers/json_monkey_patches.rb:13:in `parse'
app/controllers/magic_controller.rb:123:in `do_magic'
vendor/ruby/1.9.1/gems/actionpack-2.3.18/lib/action_controller/base.rb:1333:in `perform_action'
vendor/ruby/1.9.1/gems/actionpack-2.3.18/lib/action_controller/filters.rb:617:in `call_filters'
vendor/ruby/1.9.1/gems/actionpack-2.3.18/lib/action_controller/filters.rb:638:in `block in run_before_filters'
app/controllers/application_controller.rb:150:in `give_session_to_models'
vendor/ruby/1.9.1/gems/activesupport-2.3.18/lib/active_support/callbacks.rb:178:in `evaluate_method'
vendor/ruby/1.9.1/gems/actionpack-2.3.18/lib/action_controller/filters.rb:186:in `call'
vendor/ruby/1.9.1/gems/actionpack-2.3.18/lib/action_controller/filters.rb:635:in `run_before_filters'
vendor/ruby/1.9.1/gems/actionpack-2.3.18/lib/action_controller/filters.rb:615:in `call_filters'
vendor/ruby/1.9.1/gems/actionpack-2.3.18/lib/action_controller/filters.rb:610:in `perform_action_with_filters'
vendor/ruby/1.9.1/gems/actionpack-2.3.18/lib/action_controller/benchmarking.rb:68:in `block in perform_action_with_benchmark'
vendor/ruby/1.9.1/gems/actionpack-2.3.18/lib/action_controller/benchmarking.rb:68:in `perform_action_with_benchmark'
vendor/ruby/1.9.1/gems/actionpack-2.3.18/lib/action_controller/rescue.rb:160:in `perform_action_with_rescue'
vendor/ruby/1.9.1/gems/actionpack-2.3.18/lib/action_controller/flash.rb:151:in `perform_action_with_flash'
vendor/ruby/1.9.1/gems/actionpack-2.3.18/lib/action_controller/base.rb:532:in `process'
vendor/ruby/1.9.1/gems/actionpack-2.3.18/lib/action_controller/filters.rb:606:in `process_with_filters'
vendor/ruby/1.9.1/gems/actionpack-2.3.18/lib/action_controller/base.rb:391:in `process'
vendor/ruby/1.9.1/gems/actionpack-2.3.18/lib/action_controller/base.rb:386:in `call'
vendor/ruby/1.9.1/gems/actionpack-2.3.18/lib/action_controller/routing/route_set.rb:438:in `call'
vendor/ruby/1.9.1/gems/actionpack-2.3.18/lib/action_controller/dispatcher.rb:87:in `dispatch'
vendor/ruby/1.9.1/gems/actionpack-2.3.18/lib/action_controller/dispatcher.rb:121:in `_call'
vendor/ruby/1.9.1/gems/actionpack-2.3.18/lib/action_controller/dispatcher.rb:130:in `block in build_middleware_stack'
vendor/ruby/1.9.1/gems/actionpack-2.3.18/lib/action_controller/string_coercion.rb:25:in `call'
vendor/ruby/1.9.1/gems/actionpack-2.3.18/lib/action_controller/string_coercion.rb:25:in `call'
vendor/ruby/1.9.1/gems/actionpack-2.3.18/lib/action_controller/params_parser.rb:15:in `call'
vendor/ruby/1.9.1/gems/actionpack-2.3.18/lib/action_controller/session/abstract_store.rb:177:in `call'
vendor/ruby/1.9.1/gems/activerecord-2.3.18/lib/active_record/query_cache.rb:29:in `block in call'
vendor/ruby/1.9.1/gems/activerecord-2.3.18/lib/active_record/connection_adapters/abstract/query_cache.rb:34:in `cache'
vendor/ruby/1.9.1/gems/activerecord-2.3.18/lib/active_record/query_cache.rb:9:in `cache'