Registering & Logging In

General Questions

How to Register in the App?

To use the app, you need to install it, register, and log in using your perconal credentials.

After registration, you can log in to the app again from an unlimited number of computers and mobile devices.

Where to Get an Account?

App Log In Options

Registration and login to the app can be done in different ways. If registration without a phone number is enabled by the administrator and the corresponding login methods are available, you will see the following buttons on the app login screen:

How Does the Login Screen Appear When Registration Without Phone Number Is Unavailable?

If registration without a phone number is disabled in your organization, the login screen will contain a field for the phone number with a Log in with QR code button.

The registration and authentication scheme using a phone number in eXpress:

Can I Stay on Public Server Without Logging Into Corporate Server?

When registering with a phone number in eXpress, you can skip connecting to the corporate server and remain on the public server.

Is There an SMS Receiving Limit?

When registering or logging into eXpress using a phone number, the number of attempts to receive an SMS is limited. This block can be removed via support. There could be also a daily limit from the SMS provider (10 attempts), which cannot be removed — you must wait 24 hours.

Not Getting SMS Code? What to Do?

If the code does not arrive or an error occurs, do not request it again but contact your organization's support or the eXpress immediately.

❓Related Topics:
• SMS code is incorrect or not arriving
• Unhandled_service_error | “An error occurred” after entering the SMS code

What Does the “Leave the Server” Button Do?

When logging in again, you can leave the server using the Leave the server button (sends a request for logout). If the administrator confirms the logout, the same device will be required to log in again.

Authentication on an eXpress Lite Server

Why Is This Button Missing in the Aurora App?

⚠️ Not yet supported in the Aurora app.

I Previously Used a Phone Number. Can I Log in via Email Now?

⚠️ If you previously logged in with a phone number, it is highly recommended to use the Phone and Credentials button or connect to the corporate server in the profile settings (eXpress). Otherwise, linking a new number may result in message history loss (another account is created).

What Happens After Entering Corporate Email?

Then, depending on server settings, you may need to:

• select a server (check with your organization's support team),
• enter credentials,
• confirm login with a code from the email,
• or manually enter the server address.

What Does the “Leave the Server” Button Do?

Why Was SMS Verification Still Required?

This means the system detected a mobile phone number linked to the profile.

Phone number verification via SMS code is not performed when:

• You, as a public
  RTS
  server user, connect to a corporate
  CTS
  server via Settings > Profile in eXpress app.
• SMS verification upon login by email or server address is disabled by your corporate server administrator for the internal corporate network, and you are connecting from within it.

Why Is This Button Missing in the Aurora App?

⚠️ Not yet supported in the Aurora app.

I Previously Used a Phone Number. Can I Log in via Server Address Now?

⚠️ If you previously logged in with a phone number, it is highly recommended to use the Phone and Credentials button or connect to the corporate server in the profile settings (eXpress). Otherwise, linking a new number may result in message history loss (another account is created).

What Happens After Entering Corporate Server Address?

• If server is found — server authentication (step 2).
• If server is not found — “Corporate server address not found” error.

What Does the “Leave the Server” Button Do?

Why Was SMS Verification Still Required?

This means the system detected a mobile phone number linked to the profile.

Phone number verification via SMS code is not performed when:

• You, as a public
  RTS
  server user, connect to a corporate
  CTS
  server via Settings > Profile in eXpress app.
• SMS verification upon login by email or server address is disabled by your corporate server administrator for the internal corporate network, and you are connecting from within it.

If you are already logged into the app on one device (mobile or computer), you can quickly log in on another using QR code. Entering a password or credentials will not be required. If you have not previously logged in on other devices or cleared sessions, full authentication will be necessary.

How to Sign Into a Mobile Device via Computer?

How to Sign Into a Computer via Mobile Device?

How Often Are QR Codes Refreshed?

QR codes refresh every minute.

Can I Scan a QR Code From One Mobile Device to Another?

If you scan an eXpress Mobile code instead of eXpress Web, the error Incorrect QR Code. Try again. (Android) or Can’t parse registration JSON (iOS) will appear.

I Opened a QR Code on PC but It Disappeared. Why?

The QR code will not display on your PC if the desktop app window or web app tab is not in focus — click inside the window with your mouse.

❓Related Topics:
• “Pairing Error” when scanning QR code
• After scanning QR, the email input screen opens, followed by “Server Error”
• “Can't read RTS keys” error when logging in via QR code from iOS to web/desktop app

Is There a Session Limit?

The app can be used on an unlimited number of devices, but only one user can work in it at the same time.

Where Can I View My Sessions?

Current active sessions on other devices are displayed in the app settings under Open sessions. Your current session cannot be seen in the list. Sessions on different devices are also visible to the administrator in the “Activations” section of the admin panel. The last activity of a session is considered the time the client app connected to the server. On the corporate server, sessions have a special identifier — UDID.

I Changed the Device for Working With the App, What Should I Do?

If you are switching to a new device, follow these steps:

1. Log in on the new device using one of the following methods:
   • via QR code,
   • via the mobile phone number linked to the app,
   • via email,
   • via the corporate server address.
2. Close the session on the previous device:

   Method	Steps
   Via the previous device	Settings (avatar button) > Close session.
   Via the new device	Settings (avatar button) > Open sessions > close the session of the previous device (with the "X" button or by swiping on iOS).

❓Related Topics:
• Getting kicked out of the session, getting redirected to the app login screen

A personal password and PIN code can be created as an additional measure to protect your data. To create them, after logging into the app, open Settings (avatar button) > Additional Data Protection.

What to Do If You Forgot Your Personal Password

1. Try to recall the password: after exhausting attempts, the system will return you to the initial login page, where you can try again.
2. The personal password can be changed if the app is open on another device (e.g., you are logging into the mobile app while an active session is running on the web app on a computer, or vice versa). The password is changed in settings:

   App Version	How to Change the Personal Password
   Android	Settings (avatar button) > Additional Data Protection > enter a new password and confirmation > Done
   iOS	Settings (avatar button) > Security > Additional Data Protection > enter a new password and confirmation > Done
   Web/Desktop	Settings (avatar button) > Main Settings > Additional Data Protection > enter a new password and confirmation > Done

3. If you are already using the app on a computer, you can log into the mobile version via a QR code, and vice versa:

   Device	Steps
   Logging into the mobile app via a computer	In the desktop/web app, select Settings (avatar button) > Open Sessions > eXpress mobile. In the mobile app, on the login screen, tap Log in via QR code and scan the code from the computer screen. No credentials will be required.
   Logging into the computer via a mobile device	In the mobile app, select Settings (avatar button) > eXpress WEB. On the computer, return to the QR code screen (you may need to click Back to start or Clear data) and scan it from your phone. No credentials will be required.

4. Or reset the password by selecting Reset Password on the login screen.
   
   ⚠️ Resetting your personal password will irreversibly revoke access to all chats, as new encryption keys will be generated. If you change the password (instead of resetting it), the chats will remain intact because the keys stay the same.
   Resetting the password terminates all active sessions (you will be logged out), while changing the password does not (sessions remain active).
   For Administrators: How to Find Out If a User's Personal Password Was Reset

   CTS

   eCTS

   In the admin panel, in the Audit section, the event cts_key_updated indicates that the password was reset — the user now has new encryption keys. These events can be checked since version 3.60.

What to Do If You Forgot Your PIN Code

On the PIN code entry screen, tap Forgot PIN?. The current PIN code will be deleted, the session will end, and you will need to log in again. No data will be lost. If necessary, you can set a new PIN code.

❓Related Topics:
• Role Model Rule “Mandatory PIN Code”

Additional Data Protection — Questions

Is Personal Password Creation Required?

No, it is not. In previous versions of the app (before 2.21 for mobile and before 2.6 for web/desktop), a personal password was mandatory during registration.

How to Find Out If a Personal Password Is Set on My Account?

Open the Additional Data Protection section in the app settings — if there is a Refuse Password button, a password is set.

If the Additional Data Protection section does not have a Refuse Password button, it means you have already opted out or never created one.

Who Can Manage My Personal Password?

Only you know your personal password and PIN code. Neither the vendor, developers, nor administrators can recover or change them.

I Connected to a Different Server — Why Do I Still Need to Enter My Personal Password?

The personal password is linked to a personal account. If the same phone number is used for login, the password will be required even when switching between corporate servers — until you opt out of it.

How Can I Stop Using a Personal Password?

You can opt out of the personal password without losing chats in Settings (avatar button) > Additional Data Protection by the Refuse Password button, but this is not recommended, as it lowers data security.

Why Was I Asked to Create a PIN When Registering?

Depending on your organization's role model configuration, you may also be required to create a PIN code during registration.

Can I Use Biometrics Instead of a PIN Code?

On mobile devices, when the PIN code is enabled, biometrics can be used instead of entering the code.

If you encounter issues with registration or signing in to the app, try clearing the local cache.

Check the instructions for the error below. If that doesn’t help, collect the app sign-in logs and contact eXpress support.

App Asks You to Enter Letters or Listen to Audio Against Background Noise (Captcha)

To protect eXpress from SMS spam, a Captcha is used. On some devices that the system deems suspicious, you might be asked to pass a verification: enter letters by reading them from an image or listening to an audio clip.

The following can help reduce the likelihood of this verification appearing:

• Regularly update your browser and your device's operating system. Don't use outdated devices.
• Disable third-party extensions and ad blockers in your browser.
• Try to avoid connecting to public WiFi networks in public places (subway, cafes, airports).
• Make sure the system time on your device is synchronized — more details.

Error After Requesting an SMS Code | SMS Code Is Incorrect or Not Received

Possible errors:

• “The server is temporarily unavailable”
• “The server with the specified hostname could not be found”
• “Error sending SMS, try again later”

Having Trouble Connecting?

Disable VPN or proxy, try another network.

Did You Change Your SIM?

If you recently changed your SIM card or mobile carrier, wait 24 hours.

Entered Something Wrong?

Check your phone number. Only mobile numbers are supported. Ensure the country is correct — some SMS providers do not send codes to certain countries.

Check the code input. Each code is valid until a new one is requested. SMS requests can be sent no more than once per minute.

Requested SMS Too Many Times?

Ensure you haven’t exceeded the SMS code limit. For eXpress — no more than 7 requests per day. In a custom ETS app, the limit may differ. If the limit is exceeded, contact eXpress support.

Server Issues?

If the account is linked to a non-working corporate server, contact eXpress support.

Mobile Provider Blocking SMS?

There may be issues with the SMS provider or carrier. Ensure the carrier hasn’t blocked automated SMS or restricted SMS codes.

“URL Not Supported” When Requesting an SMS Code on iOS

Reinstall the app. If that doesn’t help, contact eXpress support.

Unhandled_service_error | “An Error Occurred” After Entering the SMS Code

The error may only appear in the logs.

Possible causes

• The corporate server is unavailable or data is incorrect.
• The server certificate is expired or issued incorrectly.
• Rarely—account deletion and re-registration are required (see below).

How to Resolve This?

Contact your organization’s support team or eXpress support.

For Administrators: Certificate Issues

CTS

ETS

eCTS

Errors in the browser console ((Fn +) F12 > Console tab): ERR_CERT_AUTHORITY_INVALID, or in the authentication logs: Trust anchor for certification path not found, javax.net.ssl.SSLHandshakeException: Handshake failed, indicate certificate issues. Check:

• Device certificates (instructions).
• Server certificate validity and correctness (documentation).

“Login Without a Phone Number Is Not Allowed” Error

The error occurs when trying to sign in via email or server address.

How to Resolve This?

The administrator has disabled sign-in without a phone number. Use a phone number.

“Invalid Credentials” (Incorrect Login or Password for Corporate Account)

The authentication logs will show the invalidCredentials error.

How to Resolve This?

Check the corporate server sign-in details. The username, password, and server address can be confirmed with your organization’s support team.

Maximum Number of Authentication Attempts Exceeded

The Active Directory login attempt limit has been triggered. This block will be lifted automatically (default: after 10 minutes). If you’re signed in on another device, use the QR code. If the password is lost or you can’t sign in, contact your organization’s support team.

For administrators: In the “Audit” section, this appears as the max_failed_login_attempts_reached error.

“User Not Found”, “User Not Registered on the Server”, or “Email or Login Not Found” Errors

Possible causes

• Incorrect login, password, or email address entered;
• The corporate server account has not been created yet, or there is an issue with directory service synchronization.

How to Resolve This?

Check the entered data. Try entering the corporate email in lowercase. If the issue persists, contact your organization’s support team.

“User Already Registered”, “This Login Already Used”, or “This User is Already In the System” Errors

Are You Using a Different Phone Number?

Maybe you are trying to log in with a number not used during registration. Enter the original number or link a new number (if allowed by your administrator).

Is Your Account Connected to Another Server?

If you changed employers, contact the previous employer to log out the account. Corporate correspondence is company property; the former employer must log it out. The app may have had a different name, not eXpress.

Did Your Login Details Change?

If login (e.g., due to a name change in Active Directory) or password changed, contact your organization’s support team to log out the old account and switch to the new one.

Trying to Use Phone Login When You Registered Without One?

You previously logged in without a phone number, then logged in to the same server with one. These are technically different accounts. To link the number to the “numberless” account:

1. Log in with the phone number (skip corporate data entry).
2. Delete this account.
3. Log in to the corporate account without a number and link the freed number (if allowed by your administrator).

Did You Accidentally Use External Account Login?

Logging in via an external client account is not allowed. Contact your organization's support.

Trying to Log In Without Phone When Not Allowed?

If the administrator disabled numberless login, contact your organization’s support team to temporarily allow numberless login so you can add a number.

Network Errors and Connection Issues

Possible error messages

• “Network error, check your connection to the server”;
• “The server with the specified hostname could not be found”;
• “Pairing error” when scanning a QR code;
• “Your Internet connection may have been interrupted”;
• “Could not resolve host”;
• The app constantly shows “Connection”.

Are You Working on a Corporate Network with Restrictions?

Make sure that all required network accesses are open and that eXpress is not blocked on your network. More details.

Connection Problem?

• For eXpress to function properly, you need to ensure sufficient internet speed and low ping. More details.
• On mobile, switch between Wi-Fi and mobile data (LTE) or disable “Airplane mode”.
• Try tethering from another device or using a different ISP.
• Disable VPN, ViPNet, proxy, firewall, or antivirus. Add the app to exceptions. Check and grant required network access.
• In the web version, disable browser extensions or proxies (e.g., friGate) that may affect traffic.

“Pairing Error” When Logging into the Web App via QR Code?

In the browser, grant the site Access to the Local Network permission and reload the page.

Issue With Configuration Of Your Organization?

If your organization uses a third-party certificate, install it (contact your organization’s support team or eXpress support).

Still Not Working?

• Try clearing the cache or reinstalling the app.
• Wait a few minutes and try again.
• If unresolved, contact your organization’s support team or eXpress support.

“Corporate Email Not Found” Error After Entering Email

Logging In Via Corporate Email?

You selected sign-in via corporate email on the first screen. Check if the email is entered correctly, choose another sign-in method, or contact your organization’s support team or eXpress support to set up simplified authentication for automatic server discovery.

Trying to Get Code via Email?

The error appeared on the email confirmation screen. Make sure the address is entered correctly or contact your organization’s support.

Error “The entered email does not meet server requirements” After Entering Email

“Corporate Server Address Not Found” Error After Entering Server Address

Check if the address is entered correctly, whether there are any network issues, or contact your organization’s support team or eXpress support.

“Please Use a Special Application…”, “Please Use Other Application Version…” Errors

Logging Into the Wrong Application?

Is Your Account Connected to Another Server?

You changed jobs, and your previous employer did not log out of your account on the old server. Contact them or eXpress support. For details, see account logout.

Trying to Use Phone Login When You Registered Without One?

You are trying to sign in without a phone number, but the administrator has prohibited such sign-ins. For details, see sign-in with a phone number required.

Email Verification Code Not Received

If the verification code isn't delivered to your email, first check your “Spam” folder. If the message is missing or multiple colleagues experience the same issue, contact your organization's support to verify corporate server email settings.

"cts_registration_not_supported” Error When Logging in via QR Code

The issue is related to the corporate server. Contact your organization’s support team or eXpress support to restore the server.

“Connection error, please contact your administrator” Error When Logging in via Email or Server Address

Contact your organization’s support team to update the app's server part to the latest version. Until updated, only phone number or QR code login is available.

“Can't read RTS keys” Error When Logging in via QR Code from iOS to Web/Desktop App

The mobile app uses incorrect keys due to outdated version or login issue.

How to Resolve This?

1. Close the session in the iOS app.
2. Log in to the iOS app again (without QR code).
3. Retry logging in to the web/desktop app via QR code.

“Error loading public keys” in iOS App

Reinstall the app and try logging in again. If the error persists, contact eXpress support.

“Error while connecting to Active Directory via NTLM”

The issue is caused by group policy settings. Contact your organization’s support team.

“Request_invalid_signature” Or “Set the Correct Time”

The error occurs due to incorrect time settings on the device.

Setting Time Didn't Help?

“SSL Error”, “Server Connection Error”, “Connection Error” on Android When Entering Phone Number, Email, or Server Address

Update the app. If that doesn’t help, contact your organization’s support team or eXpress support.

The App is Up to Date?

Ask your organization's support for help. For Administrators: Check the certificate.

“Authentication error. Please try again later” When Scanning QR Code

If phone number login works but QR code login doesn’t, contact your organization’s support team to check the server.

Unexpected Session Logoff or Redirect to Login Screen

Was Cache Cleared?

Clearing browser cache (in web app), Android app cache, or deleting credential keys (Windows) or keychain items (macOS, Linux) in desktop version may log you out of session (learn more).

Connecting to Remote Workplace?

Use VDI after additional configuration.

Still Not Working?

If the issue persists, contact your organization’s support team or eXpress support.

Profile Creation Error | “Cannot Decrypt RTS Access Token” Error

For Administrators: Fixing RTS ID

The error may occur if:

• the user registered on the Russian
  RTS
  and then changed the country in the web app;
• the user registered on a foreign
  RTS
  but is trying to log in from a mobile device.

In this case, the registration request may be sent to the wrong

RTS

where the initial registration took place. The logs display the error:
{ "error_data": {}, "errors": [ "Cannot decrypt RTS access token" ], "reason": "request_invalid_signature", "status": "error" }
Solution: update the user’s rts_id on

CTS

by specifying the value from their personal account on

RTS

. To do this:

• Confirm the user’s rts_id with eXpress support.
• Run the following commands in the console: cd /opt/express dpl --dc exec postgres psql -U postgres \c ad_phonebook_prod update users set rts_id = 'required_rts_id' where huid = 'user_HUID';

Note: the issue is resolved in version 3.22 of the server and client software.

Warning “Add a Telephone Number: The Administrator has Prohibited Login without a Telephone Number”

If this message appears when logging into the app:

• add a phone number to the profile;
• or contact your administrator (via your organization’s support) — the requirement may need to be disabled in the server settings.

Errors “An Error has Occurred. Try Again Later” | “Number of Attempts to Send Code Exceeded” | “Confirmation limit exceeded” (Email Code)

The daily limit for sending email codes from your IP address has been exceeded. The authentication logs display the max_failed_email_sending_attempts_reached error.

How to Resolve This?

Try again in 24 hours or contact your organization's support team so the administrator can manually remove the lock.