Registration fails with "missing field key"

[MatthiasKuehneEllerhold]

Prerequisites

• I have searched the existing Closed AND Open Issues AND Discussions
• I have searched and read the documentation

Vaultwarden Support String

Your environment (Generated via diagnostics page)

• Vaultwarden version: v1.36.0
• Web-vault version: v2026.4.1
• OS/Arch: linux/x86_64
• Running within a container: false (Base: Not applicable)
• Database type: MySQL
• Database version: 10.11.14-MariaDB-0+deb12u2-log
• Uses config.json: true
• Uses a reverse proxy: true
• IP Header check: true (X-Real-IP)
• Internet access: true
• Internet access via a proxy: false
• DNS Check: true
• Browser/Server Time Check: true
• Server/NTP Time Check: true
• Domain Configuration Check: true
• HTTPS Check: true
• Websocket Check: true
• HTTP Response Checks: false

Config & Details (Generated via diagnostics page)

Show Config & Details

Environment settings which are overridden: ADMIN_TOKEN

Failed HTTP Checks:

2FA Connector calls:
Header: 'x-frame-options' is present while it should not

Config:

{
  "_duo_akey": null,
  "_enable_duo": false,
  "_enable_email_2fa": true,
  "_enable_smtp": true,
  "_enable_yubico": true,
  "_icon_service_csp": "",
  "_icon_service_url": "",
  "_ip_header_enabled": true,
  "_max_note_size": 10000,
  "_smtp_img_src": "***:",
  "admin_ratelimit_max_burst": 3,
  "admin_ratelimit_seconds": 300,
  "admin_session_lifetime": 20,
  "admin_token": "***",
  "allowed_connect_src": "",
  "allowed_iframe_ancestors": "",
  "attachments_folder": "/var/lib/vaultwarden/attachments",
  "auth_request_purge_schedule": "30 * * * * *",
  "authenticator_disable_time_drift": false,
  "data_folder": "/var/lib/vaultwarden",
  "database_conn_init": "",
  "database_idle_timeout": 600,
  "database_max_conns": 10,
  "database_min_conns": 2,
  "database_timeout": 30,
  "database_url": "*****://**********************************************************************************",
  "db_connection_retries": 15,
  "disable_2fa_remember": false,
  "disable_admin_token": false,
  "disable_icon_download": false,
  "dns_prefer_ipv6": false,
  "domain": "*****://********************",
  "domain_origin": "*****://********************",
  "domain_path": "",
  "domain_set": true,
  "duo_context_purge_schedule": "30 * * * * *",
  "duo_host": null,
  "duo_ikey": null,
  "duo_skey": null,
  "duo_use_iframe": false,
  "email_2fa_auto_fallback": false,
  "email_2fa_enforce_on_verified_invite": false,
  "email_attempts_limit": 3,
  "email_change_allowed": true,
  "email_expiration_time": 600,
  "email_token_size": 6,
  "emergency_access_allowed": true,
  "emergency_notification_reminder_schedule": "0 3 * * * *",
  "emergency_request_timeout_schedule": "0 7 * * * *",
  "enable_db_wal": true,
  "enable_websocket": true,
  "enforce_single_org_with_reset_pw_policy": false,
  "event_cleanup_schedule": "0 10 0 * * *",
  "events_days_retain": null,
  "experimental_client_feature_flags": "",
  "extended_logging": true,
  "helo_name": null,
  "hibp_api_key": null,
  "http_request_block_non_global_ips": true,
  "http_request_block_regex": null,
  "icon_blacklist_non_global_ips": true,
  "icon_blacklist_regex": null,
  "icon_cache_folder": "/var/lib/vaultwarden/icon_cache",
  "icon_cache_negttl": 259200,
  "icon_cache_ttl": 2592000,
  "icon_download_timeout": 10,
  "icon_redirect_code": 302,
  "icon_service": "internal",
  "incomplete_2fa_schedule": "30 * * * * *",
  "incomplete_2fa_time_limit": 3,
  "increase_note_size_limit": false,
  "invitation_expiration_hours": 120,
  "invitation_org_name": "Vaultwarden",
  "invitations_allowed": true,
  "ip_header": "X-Real-IP",
  "job_poll_interval_ms": 30000,
  "log_file": "/var/log/vaultwarden/vaultwarden.log",
  "log_level": "warn",
  "log_timestamp_format": "%Y-%m-%d %H:%M:%S.%3f",
  "login_ratelimit_max_burst": 10,
  "login_ratelimit_seconds": 60,
  "org_attachment_limit": null,
  "org_creation_users": "*************************,****************************,***************************,*******************************,***************",
  "org_events_enabled": false,
  "org_groups_enabled": false,
  "password_hints_allowed": true,
  "password_iterations": 100000,
  "purge_incomplete_sso_auth": "0 20 0 * * *",
  "push_enabled": false,
  "push_identity_uri": "https://identity.bitwarden.com",
  "push_installation_id": "***",
  "push_installation_key": "***",
  "push_relay_uri": "https://push.bitwarden.com",
  "reload_templates": false,
  "require_device_email": false,
  "rsa_key_filename": "/var/lib/vaultwarden/rsa_key",
  "send_purge_schedule": "0 5 * * * *",
  "sendmail_command": null,
  "sends_allowed": true,
  "sends_folder": "/var/lib/vaultwarden/sends",
  "show_password_hint": false,
  "signups_allowed": true,
  "signups_domains_whitelist": "",
  "signups_verify": false,
  "signups_verify_resend_limit": 6,
  "signups_verify_resend_time": 3600,
  "smtp_accept_invalid_certs": false,
  "smtp_accept_invalid_hostnames": false,
  "smtp_auth_mechanism": null,
  "smtp_debug": false,
  "smtp_embed_images": true,
  "smtp_explicit_tls": null,
  "smtp_from": "***************",
  "smtp_from_name": "***********",
  "smtp_host": "*****************",
  "smtp_password": "***",
  "smtp_port": 587,
  "smtp_security": "starttls",
  "smtp_ssl": null,
  "smtp_timeout": 15,
  "smtp_username": "***************",
  "sso_allow_unknown_email_verification": false,
  "sso_audience_trusted": null,
  "sso_auth_only_not_session": false,
  "sso_authority": "",
  "sso_authorize_extra_params": "",
  "sso_callback_path": "*****://*************************************************",
  "sso_client_cache_expiration": 0,
  "sso_client_id": "",
  "sso_client_secret": "***",
  "sso_debug_tokens": false,
  "sso_enabled": false,
  "sso_master_password_policy": null,
  "sso_only": false,
  "sso_pkce": true,
  "sso_scopes": "email profile",
  "sso_signups_match_email": true,
  "templates_folder": "/var/lib/vaultwarden/templates",
  "tmp_folder": "/var/lib/vaultwarden/tmp",
  "trash_auto_delete_days": null,
  "trash_purge_schedule": "0 5 0 * * *",
  "use_sendmail": false,
  "use_syslog": false,
  "user_attachment_limit": null,
  "user_send_limit": null,
  "web_vault_enabled": true,
  "web_vault_folder": "/usr/share/vaultwarden/web-vault",
  "yubico_client_id": null,
  "yubico_secret_key": null,
  "yubico_server": null
}

Vaultwarden Build Version

1.36.0-1+1.1, webvault: 2026.4.1-1+1.1

Deployment method

OS Package (apt, yum/dnf, pacman, apk, nix, ...)

Custom deployment method

No response

Reverse Proxy

2.4.67-1~deb12u2

Host/Server Operating System

Linux

Operating System Version

Debian 12

Clients

Desktop

Client Version

2026.5.0

Steps To Reproduce

1. Use the Bitwarden App 2026.5.0 (62263) in MacOS
2. Try to register a new account
3. It fails!

Using the web GUI works though!

Expected Result

Registration via the App works.

Actual Result

Registration errors out.

Logs

[2026-06-03 09:15:18.542][vaultwarden::api::identity::_][WARN] Data guard `Json < RegisterData >` failed: Parse("{\"email\“:\“my@domain.de\“,\“masterPasswordHint\":\"\",\"userAsymmetricKeys\":{\"publicKey\“:\“REDACTED\“},\“masterPasswordAuthentication\":{\"salt\“:\“my@domain.de\“,\“kdf\":{\"iterations\":600000,\"kdfType\":0},\"masterPasswordAuthenticationHash\":\"REDACTED\"},\"masterPasswordUnlock\":{\"salt\“:\“my@domain.de\",\"kdf\":{\"iterations\":600000,\"kdfType\":0},\"masterKeyWrappedUserKey\":\"REDACTED\"},\"emailVerificationToken\": REDACTED\"}", Error("missing field `key`", line: 1, column: 3375)).

Screenshots or Videos

No response

Additional Context

No response

[stefan0xC]

Yes, that is currently impossible. As explained in the wiki this can happen when there is a breaking change made by Bitwarden, since we don't control the clients (and can only make sure the web-vault is compatible). So until we implement the new API, Vaultwarden is currently not compatible with clients with version 2026.5.0 (or later). Cf. dani-garcia/bw_web_builds#245

[GuilhermeNobre]

Yes, that is currently impossible. As explained in the wiki this can happen when there is a breaking change made by Bitwarden, since we don't control the clients (and can only make sure the web-vault is compatible). So until we implement the new API, Vaultwarden is currently not compatible with clients with version 2026.5.0 (or later). Cf. dani-garcia/bw_web_builds#245

This error apply to extensions? I'm trying connect to extensions on Google Chrome or chromium and is not working

[stefan0xC]

This error apply to extensions? I'm trying connect to extensions on Google Chrome or chromium and is not working

It applies to everything that uses the new registration API. I don't want to come across as rude but this bug report is specifically about registration and likely has nothing to do with connecting an extension (as far as I've tested it that still works without issue). Since the issue tracker is not meant as a support forum I want to ask that you open a separate thread in discussions and provide more details like the support string from the Vaultwarden admin panel.