Deleting group or project fails with Gitlab::HTTP::BlockedUrlError

Hi

After restoring a backup on a newly installed self-managed instance running gitlab-ce 15.11, I needed to delete several groups and projects
Everything went fine for most of the items, but I have a few groups and projects that can’t be deleted.
When requesting the deletion, it is scheduled as expected, but the items are still here after a few hours…

When looking at sidekiq’s logs, I see the deletion fails with the following error :

    "exception.class": "Gitlab::HTTP::BlockedUrlError",
    "exception.message": "URL is blocked: Only allowed schemes are http, https",
    "exception.backtrace": [
        "lib/gitlab/http_connection_adapter.rb:50:in `rescue in validate_url!'",
        "lib/gitlab/http_connection_adapter.rb:43:in `validate_url!'",
        "lib/gitlab/http_connection_adapter.rb:27:in `connection'",
        "lib/gitlab/http.rb:55:in `perform_request'",
        "lib/mattermost/session.rb:81:in `block in get'",
        "lib/mattermost/session.rb:180:in `handle_exceptions'",
        "lib/mattermost/session.rb:80:in `get'",
        "lib/mattermost/session.rb:130:in `oauth_uri'",
        "lib/mattermost/session.rb:108:in `create'",
        "lib/mattermost/session.rb:44:in `block in with_session'",
        "lib/mattermost/session.rb:164:in `with_lease'",
        "lib/mattermost/session.rb:43:in `with_session'",
        "lib/mattermost/client.rb:14:in `with_session'",
        "lib/mattermost/client.rb:46:in `session_delete'",
        "lib/mattermost/team.rb:23:in `destroy'",
        "app/models/chat_team.rb:10:in `remove_mattermost_team'",
        "app/services/groups/destroy_service.rb:34:in `execute'",
        "app/workers/group_destroy_worker.rb:25:in `perform'",
        "lib/gitlab/database/load_balancing/sidekiq_server_middleware.rb:26:in `call'",
        "lib/gitlab/sidekiq_middleware/duplicate_jobs/strategies/until_executed.rb:17:in `perform'",
        "lib/gitlab/sidekiq_middleware/duplicate_jobs/duplicate_job.rb:44:in `perform'",
        "lib/gitlab/sidekiq_middleware/duplicate_jobs/server.rb:8:in `call'",
        "lib/gitlab/sidekiq_middleware/worker_context.rb:9:in `wrap_in_optional_context'",
        "lib/gitlab/sidekiq_middleware/worker_context/server.rb:19:in `block in call'",
        "lib/gitlab/application_context.rb:118:in `block in use'",
        "lib/gitlab/application_context.rb:118:in `use'",
        "lib/gitlab/application_context.rb:57:in `with_context'",
        "lib/gitlab/sidekiq_middleware/worker_context/server.rb:17:in `call'",
        "lib/gitlab/sidekiq_status/server_middleware.rb:7:in `call'",
        "lib/gitlab/sidekiq_versioning/middleware.rb:9:in `call'",
        "lib/gitlab/sidekiq_middleware/query_analyzer.rb:7:in `block in call'",
        "lib/gitlab/database/query_analyzer.rb:37:in `within'",
        "lib/gitlab/sidekiq_middleware/query_analyzer.rb:7:in `call'",
        "lib/gitlab/sidekiq_middleware/admin_mode/server.rb:14:in `call'",
        "lib/gitlab/sidekiq_middleware/instrumentation_logger.rb:9:in `call'",
        "lib/gitlab/sidekiq_middleware/batch_loader.rb:7:in `call'",
        "lib/gitlab/sidekiq_middleware/extra_done_log_metadata.rb:7:in `call'",
        "lib/gitlab/sidekiq_middleware/request_store_middleware.rb:10:in `block in call'",
        "lib/gitlab/with_request_store.rb:17:in `enabling_request_store'",
        "lib/gitlab/with_request_store.rb:10:in `with_request_store'",
        "lib/gitlab/sidekiq_middleware/request_store_middleware.rb:9:in `call'",
        "lib/gitlab/sidekiq_middleware/server_metrics.rb:76:in `block in call'",
        "lib/gitlab/sidekiq_middleware/server_metrics.rb:103:in `block in instrument'",
        "lib/gitlab/metrics/background_transaction.rb:33:in `run'",
        "lib/gitlab/sidekiq_middleware/server_metrics.rb:103:in `instrument'",
        "lib/gitlab/sidekiq_middleware/server_metrics.rb:75:in `call'",
        "lib/gitlab/sidekiq_middleware/monitor.rb:10:in `block in call'",
        "lib/gitlab/sidekiq_daemon/monitor.rb:46:in `within_job'",
        "lib/gitlab/sidekiq_middleware/monitor.rb:9:in `call'",
        "lib/gitlab/sidekiq_middleware/size_limiter/server.rb:13:in `call'",
        "lib/gitlab/sidekiq_logging/structured_logger.rb:21:in `call'"
    ],
    "exception.cause_class": "Gitlab::UrlBlocker::BlockedUrlError",
 

The backup was made using a gitlab-ce instance running 15.11 version (after upgrades)
I also see many dead jobs in background job panel with the task GroupDestroyWorker having the “Gitlab::HTTP::BlockedUrlError: URL is blocked: Only allowed schemes are http, https” error
I only have the issue with very few groups and projects

Thanks for the help