Cannot enable direct transfer

Gitlab CE 15.7.1 Omnibus installation

I would like to enable direct transfer of groups and projects.
I go to Admin, Settings, General, Visibility, disable all Import sources and enable “Enable migrating GitLab groups and projects by direct transfer”.

All other options are default. When I click on “Save changes”, I get a 500 error and this in the logfile:

gitlab-rails/production_json.log:{"method":"PATCH","path":"/admin/application_settings/general","format":"html","controller":"Admin::ApplicationSettingsController","action":"general","status":500,"time":"2023-01-11T14:03:04.791Z","params":[{"key":"_method","value":"patch"},{"key":"authenticity_token","value":"[FILTERED]"},{"key":"application_setting","value":{"default_project_creation":"2","default_project_visibility":"0","default_snippet_visibility":"0","default_group_visibility":"0","restricted_visibility_levels":[""],"import_sources":[""],"project_export_enabled":"1","bulk_import_enabled":"1","enabled_git_access_protocol":"","custom_http_clone_url_root":"","rsa_key_restriction":"0","dsa_key_restriction":"0","ecdsa_key_restriction":"0","ed25519_key_restriction":"0","ecdsa_sk_key_restriction":"0","ed25519_sk_key_restriction":"0","disable_feed_token":"[FILTERED]"}}],"correlation_id":"81553808-e619-4a60-83ec-dab66a65b671","meta.caller_id":"Admin::ApplicationSettingsController#general","meta.remote_ip":"10.228.82.17","meta.feature_category":"not_owned","meta.user":"root","meta.user_id":1,"meta.client_id":"user/1","remote_ip":"10.228.82.17","user_id":1,"username":"root","ua":"Mozilla/5.0 (X11; Linux x86_64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/109.0.0.0 Safari/537.36","request_urgency":"default","target_duration_s":1,"redis_calls":18,"redis_allowed_cross_slot_calls":1,"redis_duration_s":0.0027010000000000003,"redis_read_bytes":2739,"redis_write_bytes":2545,"redis_cache_calls":13,"redis_cache_duration_s":0.001647,"redis_cache_read_bytes":2556,"redis_cache_write_bytes":754,"redis_sessions_calls":4,"redis_sessions_allowed_cross_slot_calls":1,"redis_sessions_duration_s":0.000791,"redis_sessions_read_bytes":183,"redis_sessions_write_bytes":1685,"redis_shared_state_calls":1,"redis_shared_state_duration_s":0.000263,"redis_shared_state_write_bytes":106,"db_count":7,"db_write_count":2,"db_cached_count":1,"db_replica_count":0,"db_primary_count":7,"db_main_count":7,"db_main_replica_count":0,"db_replica_cached_count":0,"db_primary_cached_count":1,"db_main_cached_count":1,"db_main_replica_cached_count":0,"db_replica_wal_count":0,"db_primary_wal_count":0,"db_main_wal_count":0,"db_main_replica_wal_count":0,"db_replica_wal_cached_count":0,"db_primary_wal_cached_count":0,"db_main_wal_cached_count":0,"db_main_replica_wal_cached_count":0,"db_replica_duration_s":0.0,"db_primary_duration_s":0.009,"db_main_duration_s":0.009,"db_main_replica_duration_s":0.0,"cpu_s":0.068938,"mem_objects":47576,"mem_bytes":3777931,"mem_mallocs":10065,"mem_total_bytes":5680971,"pid":249304,"worker_id":"puma_0","rate_limiting_gates":[],"exception.class":"OpenSSL::Cipher::CipherError","exception.message":"","exception.backtrace":["lib/gitlab/database/load_balancing/connection_proxy.rb:120:in block in write_using_load_balancer’",“lib/gitlab/database/load_balancing/load_balancer.rb:129:in block in read_write'","lib/gitlab/database/load_balancing/load_balancer.rb:200:in retry_with_backoff’”,“lib/gitlab/database/load_balancing/load_balancer.rb:118:in read_write'","lib/gitlab/database/load_balancing/connection_proxy.rb:119:in write_using_load_balancer’”,“lib/gitlab/database/load_balancing/connection_proxy.rb:71:in transaction'","app/services/application_settings/update_service.rb:50:in update_settings’”,“app/services/application_settings/update_service.rb:12:in execute'","app/controllers/admin/application_settings_controller.rb:291:in perform_update’”,“app/controllers/admin/application_settings_controller.rb:55:in block (2 levels) in <class:ApplicationSettingsController>'","app/controllers/application_controller.rb:533:in set_current_admin’”,“lib/gitlab/session.rb:11:in with_session'","app/controllers/application_controller.rb:524:in set_session_storage’”,“lib/gitlab/i18n.rb:107:in with_locale'","lib/gitlab/i18n.rb:113:in with_user_locale’”,“app/controllers/application_controller.rb:512:in set_locale'","app/controllers/application_controller.rb:506:in set_current_context’”,“lib/gitlab/metrics/elasticsearch_rack_middleware.rb:16:in call'","lib/gitlab/middleware/memory_report.rb:13:in call’”,“lib/gitlab/middleware/speedscope.rb:13:in call'","lib/gitlab/database/load_balancing/rack_middleware.rb:23:in call’”,“lib/gitlab/middleware/rails_queue_duration.rb:33:in call'","lib/gitlab/metrics/rack_middleware.rb:16:in block in call’”,“lib/gitlab/metrics/web_transaction.rb:46:in run'","lib/gitlab/metrics/rack_middleware.rb:16:in call’”,“lib/gitlab/jira/middleware.rb:19:in call'","lib/gitlab/middleware/go.rb:20:in call’”,“lib/gitlab/etag_caching/middleware.rb:21:in call'","lib/gitlab/middleware/query_analyzer.rb:11:in block in call’”,“lib/gitlab/database/query_analyzer.rb:37:in within'","lib/gitlab/middleware/query_analyzer.rb:11:in call’”,“lib/gitlab/middleware/multipart.rb:173:in call'","lib/gitlab/middleware/read_only/controller.rb:50:in call’”,“lib/gitlab/middleware/read_only.rb:18:in call'","lib/gitlab/middleware/same_site_cookies.rb:27:in call’”,“lib/gitlab/middleware/handle_malformed_strings.rb:21:in call'","lib/gitlab/middleware/basic_health_check.rb:25:in call’”,“lib/gitlab/middleware/handle_ip_spoof_attack_error.rb:25:in call'","lib/gitlab/middleware/request_context.rb:21:in call’”,“lib/gitlab/middleware/webhook_recursion_detection.rb:15:in call'","config/initializers/fix_local_cache_middleware.rb:11:in call’”,“lib/gitlab/middleware/compressed_json.rb:37:in call'","lib/gitlab/middleware/rack_multipart_tempfile_factory.rb:19:in call’”,“lib/gitlab/middleware/sidekiq_web_static.rb:20:in call'","lib/gitlab/metrics/requests_rack_middleware.rb:77:in call’”,"lib/gitlab/middleware/release_env.rb:13:in call'"],"db_duration_s":0.18064,"view_duration_s":0.0,"duration_s":0.22379}

Is there any unmentioned but needed setting in gitlab.rb?

Thanks for any tip or help in advance.

anybody?