Please report this on the nForum in the nLab Technical Matters category. Please give as precise details as you can as to what triggered the error.

nLab home page

Here is the error:

undefined method `content' for nil:NilClass

And here is the exception backtrace:

/home/nlab/www/nlab/app/controllers/wiki_controller.rb:678:in `tex'
/home/nlab/www/nlab/vendor/rails/actionpack/lib/action_controller/base.rb:1333:in `perform_action'
/home/nlab/www/nlab/vendor/rails/actionpack/lib/action_controller/filters.rb:617:in `call_filters'
/home/nlab/www/nlab/vendor/rails/actionpack/lib/action_controller/filters.rb:638:in `block in run_before_filters'
/home/nlab/www/nlab/vendor/rails/actionpack/lib/action_controller/filters.rb:206:in `block in around_proc'
/home/nlab/www/nlab/vendor/rails/activesupport/lib/active_support/callbacks.rb:182:in `evaluate_method'
/home/nlab/www/nlab/vendor/rails/actionpack/lib/action_controller/filters.rb:184:in `call'
/home/nlab/www/nlab/vendor/rails/actionpack/lib/action_controller/filters.rb:635:in `run_before_filters'
/home/nlab/www/nlab/vendor/rails/actionpack/lib/action_controller/filters.rb:615:in `call_filters'
/home/nlab/www/nlab/vendor/rails/actionpack/lib/action_controller/filters.rb:638:in `block in run_before_filters'
/home/nlab/www/nlab/vendor/rails/actionpack/lib/action_controller/filters.rb:189:in `call'
/home/nlab/www/nlab/vendor/rails/actionpack/lib/action_controller/filters.rb:635:in `run_before_filters'
/home/nlab/www/nlab/vendor/rails/actionpack/lib/action_controller/filters.rb:615:in `call_filters'
/home/nlab/www/nlab/vendor/rails/actionpack/lib/action_controller/filters.rb:638:in `block in run_before_filters'
/home/nlab/www/nlab/vendor/rails/actionpack/lib/action_controller/caching/actions.rb:91:in `filter'
/home/nlab/www/nlab/vendor/rails/actionpack/lib/action_controller/caching/actions.rb:66:in `block in caches_action'
/home/nlab/www/nlab/vendor/rails/activesupport/lib/active_support/callbacks.rb:182:in `evaluate_method'
/home/nlab/www/nlab/vendor/rails/actionpack/lib/action_controller/filters.rb:184:in `call'
/home/nlab/www/nlab/vendor/rails/actionpack/lib/action_controller/filters.rb:635:in `run_before_filters'
/home/nlab/www/nlab/vendor/rails/actionpack/lib/action_controller/filters.rb:615:in `call_filters'
/home/nlab/www/nlab/vendor/rails/actionpack/lib/action_controller/filters.rb:610:in `perform_action_with_filters'
/home/nlab/www/nlab/vendor/rails/actionpack/lib/action_controller/benchmarking.rb:68:in `block in perform_action_with_benchmark'
/home/nlab/www/nlab/vendor/rails/activesupport/lib/active_support/core_ext/benchmark.rb:17:in `block in ms'
/usr/share/ruby/benchmark.rb:308:in `realtime'
/home/nlab/www/nlab/vendor/rails/activesupport/lib/active_support/core_ext/benchmark.rb:17:in `ms'
/home/nlab/www/nlab/vendor/rails/actionpack/lib/action_controller/benchmarking.rb:68:in `perform_action_with_benchmark'
/home/nlab/www/nlab/vendor/rails/actionpack/lib/action_controller/rescue.rb:160:in `perform_action_with_rescue'
/home/nlab/www/nlab/vendor/rails/actionpack/lib/action_controller/flash.rb:151:in `perform_action_with_flash'
/home/nlab/www/nlab/vendor/rails/actionpack/lib/action_controller/base.rb:532:in `process'
/home/nlab/www/nlab/vendor/rails/actionpack/lib/action_controller/filters.rb:606:in `process_with_filters'
/home/nlab/www/nlab/vendor/rails/actionpack/lib/action_controller/base.rb:391:in `process'
/home/nlab/www/nlab/vendor/rails/actionpack/lib/action_controller/base.rb:386:in `call'
/home/nlab/www/nlab/vendor/rails/actionpack/lib/action_controller/routing/route_set.rb:438:in `call'
/home/nlab/www/nlab/vendor/rails/actionpack/lib/action_controller/dispatcher.rb:87:in `dispatch'
/home/nlab/www/nlab/vendor/rails/actionpack/lib/action_controller/dispatcher.rb:121:in `_call'
/home/nlab/www/nlab/vendor/rails/actionpack/lib/action_controller/dispatcher.rb:130:in `block in build_middleware_stack'
/home/nlab/www/nlab/vendor/rails/actionpack/lib/action_controller/string_coercion.rb:29:in `call'
/home/nlab/www/nlab/vendor/bundle/ruby/3.0.0/gems/rack-2.2.4/lib/rack/head.rb:12:in `call'
/home/nlab/www/nlab/vendor/bundle/ruby/3.0.0/gems/rack-2.2.4/lib/rack/method_override.rb:24:in `call'
/home/nlab/www/nlab/vendor/rails/actionpack/lib/action_controller/params_parser.rb:15:in `call'
/home/nlab/www/nlab/vendor/rails/railties/lib/rails/rack/metal.rb:47:in `call'
/home/nlab/www/nlab/vendor/rails/actionpack/lib/action_controller/session/abstract_store.rb:177:in `call'
/home/nlab/www/nlab/vendor/rails/activerecord/lib/active_record/query_cache.rb:29:in `block in call'
/home/nlab/www/nlab/vendor/rails/activerecord/lib/active_record/connection_adapters/abstract/query_cache.rb:34:in `cache'
/home/nlab/www/nlab/vendor/rails/activerecord/lib/active_record/query_cache.rb:9:in `cache'
/home/nlab/www/nlab/vendor/rails/activerecord/lib/active_record/query_cache.rb:28:in `call'
/home/nlab/www/nlab/vendor/rails/activerecord/lib/active_record/connection_adapters/abstract/connection_pool.rb:361:in `call'
/home/nlab/www/nlab/vendor/rails/actionpack/lib/action_controller/failsafe.rb:26:in `call'
/home/nlab/www/nlab/vendor/bundle/ruby/3.0.0/gems/rack-2.2.4/lib/rack/lock.rb:18:in `call'
/home/nlab/www/nlab/vendor/rails/actionpack/lib/action_controller/dispatcher.rb:106:in `call'
/home/nlab/www/nlab/vendor/rails/railties/lib/rails/rack/static.rb:31:in `call'
/home/nlab/www/nlab/vendor/rails/railties/lib/rails/rack/log_tailer.rb:17:in `call'
/home/nlab/www/nlab/vendor/bundle/ruby/3.0.0/gems/unicorn-6.1.0/lib/unicorn/http_server.rb:634:in `process_client'
/home/nlab/www/nlab/vendor/bundle/ruby/3.0.0/gems/unicorn-6.1.0/lib/unicorn/http_server.rb:739:in `worker_loop'
/home/nlab/www/nlab/vendor/bundle/ruby/3.0.0/gems/unicorn-6.1.0/lib/unicorn/http_server.rb:547:in `spawn_missing_workers'
/home/nlab/www/nlab/vendor/bundle/ruby/3.0.0/gems/unicorn-6.1.0/lib/unicorn/http_server.rb:143:in `start'
/home/nlab/www/nlab/vendor/bundle/ruby/3.0.0/gems/unicorn-6.1.0/bin/unicorn_rails:209:in `<top (required)>'
/home/nlab/www/nlab/vendor/bundle/ruby/3.0.0/bin/unicorn_rails:25:in `load'
/home/nlab/www/nlab/vendor/bundle/ruby/3.0.0/bin/unicorn_rails:25:in `<top (required)>'
/usr/share/gems/gems/bundler-2.2.33/lib/bundler/cli/exec.rb:58:in `load'
/usr/share/gems/gems/bundler-2.2.33/lib/bundler/cli/exec.rb:58:in `kernel_load'
/usr/share/gems/gems/bundler-2.2.33/lib/bundler/cli/exec.rb:23:in `run'
/usr/share/gems/gems/bundler-2.2.33/lib/bundler/cli.rb:479:in `exec'
/usr/share/gems/gems/bundler-2.2.33/lib/bundler/vendor/thor/lib/thor/command.rb:27:in `run'
/usr/share/gems/gems/bundler-2.2.33/lib/bundler/vendor/thor/lib/thor/invocation.rb:127:in `invoke_command'
/usr/share/gems/gems/bundler-2.2.33/lib/bundler/vendor/thor/lib/thor.rb:392:in `dispatch'
/usr/share/gems/gems/bundler-2.2.33/lib/bundler/cli.rb:31:in `dispatch'
/usr/share/gems/gems/bundler-2.2.33/lib/bundler/vendor/thor/lib/thor/base.rb:485:in `start'
/usr/share/gems/gems/bundler-2.2.33/lib/bundler/cli.rb:25:in `start'
/usr/share/gems/gems/bundler-2.2.33/libexec/bundle:49:in `block in <top (required)>'
/usr/share/gems/gems/bundler-2.2.33/lib/bundler/friendly_errors.rb:103:in `with_friendly_errors'
/usr/share/gems/gems/bundler-2.2.33/libexec/bundle:37:in `<top (required)>'
/usr/bin/bundle:23:in `load'
/usr/bin/bundle:23:in `<main>'