After activating apache2 passenger log i see some errors related to outdated gems. So I updated these but now we come to this error:

[ 2018-03-02 08:25:24.6940 30999/7f9ff2ffd700 age/Cor/Con/CheckoutSession.cpp:285 ]: [Client 2-9] Cannot checkout session because a spawning error occurred. The identifier of the error is 1410e954. Please see earlier logs for details about the error.
[ 2018-03-02 08:25:24.6941 30999/7f9ff27fc700 age/Cor/Con/CheckoutSession.cpp:285 ]: [Client 3-9] Cannot checkout session because a spawning error occurred. The identifier of the error is 1410e954. Please see earlier logs for details about the error.
App 31291 stdout: 
[ 2018-03-02 08:25:25.5254 30999/7f9fb7d6b700 age/Cor/App/Implementation.cpp:304 ]: Could not spawn process for application /usr/share/foreman: An error occured while starting the web application.
  Error ID: 5b7555e5
  Error details saved to: /tmp/passenger-error-lMpRT5.html
  Message from application: PG::DuplicateTable: ERROR:  relation "dynflow_execution_plans" already exists
 (Sequel::DatabaseError)
  /usr/share/foreman/vendor/ruby/2.3.0/gems/sequel-4.15.0/lib/sequel/adapters/postgres.rb:161:in `async_exec'
  /usr/share/foreman/vendor/ruby/2.3.0/gems/sequel-4.15.0/lib/sequel/adapters/postgres.rb:161:in `block in execute_query'
  /usr/share/foreman/vendor/ruby/2.3.0/gems/sequel-4.15.0/lib/sequel/database/logging.rb:33:in `log_yield'
  /usr/share/foreman/vendor/ruby/2.3.0/gems/sequel-4.15.0/lib/sequel/adapters/postgres.rb:161:in `execute_query'
  /usr/share/foreman/vendor/ruby/2.3.0/gems/sequel-4.15.0/lib/sequel/adapters/postgres.rb:148:in `block in execute'
  /usr/share/foreman/vendor/ruby/2.3.0/gems/sequel-4.15.0/lib/sequel/adapters/postgres.rb:124:in `check_disconnect_errors'
  /usr/share/foreman/vendor/ruby/2.3.0/gems/sequel-4.15.0/lib/sequel/adapters/postgres.rb:148:in `execute'
  /usr/share/foreman/vendor/ruby/2.3.0/gems/sequel-4.15.0/lib/sequel/adapters/postgres.rb:492:in `_execute'
  /usr/share/foreman/vendor/ruby/2.3.0/gems/sequel-4.15.0/lib/sequel/adapters/postgres.rb:316:in `block (2 levels) in execute'
  /usr/share/foreman/vendor/ruby/2.3.0/gems/sequel-4.15.0/lib/sequel/adapters/postgres.rb:513:in `check_database_errors'
  /usr/share/foreman/vendor/ruby/2.3.0/gems/sequel-4.15.0/lib/sequel/adapters/postgres.rb:316:in `block in execute'
  /usr/share/foreman/vendor/ruby/2.3.0/gems/sequel-4.15.0/lib/sequel/database/connecting.rb:250:in `block in synchronize'
  /usr/share/foreman/vendor/ruby/2.3.0/gems/sequel-4.15.0/lib/sequel/connection_pool/threaded.rb:91:in `hold'
  /usr/share/foreman/vendor/ruby/2.3.0/gems/sequel-4.15.0/lib/sequel/database/connecting.rb:250:in `synchronize'
  /usr/share/foreman/vendor/ruby/2.3.0/gems/sequel-4.15.0/lib/sequel/adapters/postgres.rb:316:in `execute'
  /usr/share/foreman/vendor/ruby/2.3.0/gems/sequel-4.15.0/lib/sequel/database/query.rb:50:in `execute_dui'
  /usr/share/foreman/vendor/ruby/2.3.0/gems/sequel-4.15.0/lib/sequel/database/query.rb:43:in `execute_ddl'
  /usr/share/foreman/vendor/ruby/2.3.0/gems/sequel-4.15.0/lib/sequel/database/schema_methods.rb:639:in `create_table_from_generator'
  /usr/share/foreman/vendor/ruby/2.3.0/gems/sequel-4.15.0/lib/sequel/database/schema_methods.rb:195:in `create_table'
  /usr/share/foreman/vendor/ruby/2.3.0/gems/dynflow-0.8.29/lib/dynflow/persistence_adapters/sequel_migrations/001_initial.rb:3:in `block (2 levels) in <top (required)>'
  /usr/share/foreman/vendor/ruby/2.3.0/gems/sequel-4.15.0/lib/sequel/extensions/migration.rb:100:in `instance_eval'
  /usr/share/foreman/vendor/ruby/2.3.0/gems/sequel-4.15.0/lib/sequel/extensions/migration.rb:100:in `apply'
  /usr/share/foreman/vendor/ruby/2.3.0/gems/sequel-4.15.0/lib/sequel/extensions/migration.rb:529:in `block (2 levels) in run'
  /usr/share/foreman/vendor/ruby/2.3.0/gems/sequel-4.15.0/lib/sequel/database/transactions.rb:126:in `_transaction'
  /usr/share/foreman/vendor/ruby/2.3.0/gems/sequel-4.15.0/lib/sequel/database/transactions.rb:100:in `block in transaction'
  /usr/share/foreman/vendor/ruby/2.3.0/gems/sequel-4.15.0/lib/sequel/database/connecting.rb:250:in `block in synchronize'
  /usr/share/foreman/vendor/ruby/2.3.0/gems/sequel-4.15.0/lib/sequel/connection_pool/threaded.rb:104:in `hold'
  /usr/share/foreman/vendor/ruby/2.3.0/gems/sequel-4.15.0/lib/sequel/database/connecting.rb:250:in `synchronize'
  /usr/share/foreman/vendor/ruby/2.3.0/gems/sequel-4.15.0/lib/sequel/database/transactions.rb:89:in `transaction'
  /usr/share/foreman/vendor/ruby/2.3.0/gems/sequel-4.15.0/lib/sequel/extensions/migration.rb:464:in `checked_transaction'
  /usr/share/foreman/vendor/ruby/2.3.0/gems/sequel-4.15.0/lib/sequel/extensions/migration.rb:528:in `block in run'
  /usr/share/foreman/vendor/ruby/2.3.0/gems/sequel-4.15.0/lib/sequel/extensions/migration.rb:524:in `each'
  /usr/share/foreman/vendor/ruby/2.3.0/gems/sequel-4.15.0/lib/sequel/extensions/migration.rb:524:in `run'
  /usr/share/foreman/vendor/ruby/2.3.0/gems/sequel-4.15.0/lib/sequel/extensions/migration.rb:391:in `run'
  /usr/share/foreman/vendor/ruby/2.3.0/gems/dynflow-0.8.29/lib/dynflow/persistence_adapters/sequel.rb:238:in `migrate_db'
  /usr/share/foreman/vendor/ruby/2.3.0/gems/dynflow-0.8.29/lib/dynflow/persistence_adapters/sequel.rb:46:in `initialize'
  /usr/share/foreman/vendor/ruby/2.3.0/gems/foreman-tasks-0.10.6/lib/foreman_tasks/dynflow/configuration.rb:39:in `new'
  /usr/share/foreman/vendor/ruby/2.3.0/gems/foreman-tasks-0.10.6/lib/foreman_tasks/dynflow/configuration.rb:39:in `initialize_persistence'
  /usr/share/foreman/vendor/ruby/2.3.0/gems/dynflow-0.8.29/lib/dynflow/rails/configuration.rb:107:in `block in world_config'
  /usr/share/foreman/vendor/ruby/2.3.0/gems/dynflow-0.8.29/lib/dynflow/rails/configuration.rb:103:in `tap'
  /usr/share/foreman/vendor/ruby/2.3.0/gems/dynflow-0.8.29/lib/dynflow/rails/configuration.rb:103:in `world_config'
  /usr/share/foreman/vendor/ruby/2.3.0/gems/foreman-tasks-0.10.6/lib/foreman_tasks/dynflow/configuration.rb:8:in `world_config'
  /usr/share/foreman/vendor/ruby/2.3.0/gems/dynflow-0.8.29/lib/dynflow/rails/configuration.rb:66:in `initialize_world'
  /usr/share/foreman/vendor/ruby/2.3.0/gems/dynflow-0.8.29/lib/dynflow/rails.rb:100:in `init_world'
  /usr/share/foreman/vendor/ruby/2.3.0/gems/dynflow-0.8.29/lib/dynflow/rails.rb:37:in `initialize!'
  /usr/share/foreman/vendor/ruby/2.3.0/gems/foreman-tasks-0.10.6/lib/foreman_tasks/engine.rb:153:in `block (2 levels) in <class:Engine>'
  /usr/lib/ruby/vendor_ruby/phusion_passenger/public_api.rb:42:in `block in call_event'
  /usr/lib/ruby/vendor_ruby/phusion_passenger/public_api.rb:41:in `each'
  /usr/lib/ruby/vendor_ruby/phusion_passenger/public_api.rb:41:in `call_event'
  /usr/lib/ruby/vendor_ruby/phusion_passenger/loader_shared_helpers.rb:393:in `before_handling_requests'
  /usr/share/passenger/helper-scripts/rack-preloader.rb:134:in `negotiate_spawn_command'
  /usr/share/passenger/helper-scripts/rack-preloader.rb:158:in `<module:App>'
  /usr/share/passenger/helper-scripts/rack-preloader.rb:30:in `<module:PhusionPassenger>'
  /usr/share/passenger/helper-scripts/rack-preloader.rb:29:in `<main>'

I try already to uninstall the dynflow extensions but this doesn't solve the problem.

Fix was as mentioned in #12993 to delete all dynflow tables from database.

Christian Meißner wrote:

After activating apache2 passenger log i see some errors related to outdated gems. So I updated these but now we come to this error:

[...]

I try already to uninstall the dynflow extensions but this doesn't solve the problem.

I guess it's something similar to #20050 - could you try the workaround described there (gem downgrade)

Michael Moll wrote:

I guess it's something similar to #20050 - could you try the workaround described there (gem downgrade)

No i can't try because all is running after delete all dynflow tables.