Support Center / Troubleshooting / Solutions to OpenVPN Authentication Failure

Solutions to OpenVPN Authentication Failure

Encountering Authentication Failure errors when connecting to Proton VPN while using 3rd party VPN clients? Read on to find a list of solutions to this problem.

There are a number of ways to connect to Proton VPN other than using our native apps . It is also possible to connect using third party OpenVPN clienct such as Tunnelblick on Mac, OpenVPN on Linux, and different mobile clients on iOS and Android.

What is an Authentication Failure error and why does it appear?

It can be that some connection attempts will throw an AUTH FAILED error message and depending on your device and operating system, the message will look similar to the following:

Auth_Failed on the OpenVPN for Android client
Auth Failed on Linux – Ubuntu command line

This error message is thrown by the OpenVPN protocol and can mean one of two things:

  1. The credentials are incorrect, caused for example by using the wrong set of credentials, a typo when entering your username and password, a recent password change; or
  2. You have hit your maximum number of concurrent sessions. Different plans have different maximum number of simultaneous sessions. Free users get 1 connection, while Proton Plus users get up to ten connections. For more details, check out the different Proton VPN Plans.

Quick steps to fix an Authentication Failure error

If you encounter this error, there are a number of things you can try to remedy this situation. Please try the following steps to fix the problem:

1. Verify that you’re using correct OpenVPN credentials

Make sure you are using your OpenVPN credentials (and not your Proton credentials). Proton VPN employs two sets of credentials, your Proton account credentials, used to log in on our homepage (or to your email if you are a Proton Mail user), and your OpenVPN credentials, which are used to authenticate with the VPN servers if you are using a 3rd party OpenVPN application.

For security reasons, you must use your OpenVPN credentials and not your Proton credentials when logging in via third party VPN applications. See this article for details on where to find and set your OpenVPN credentials.

2. Confirm that you’re accessing servers which are available for you Proton VPN plan

Check that the server you are trying to connect to is available for your subscription. Proton VPN has different plan offerings and each tier has access to a different set of servers.

For example Proton VPN Free users only get access to free servers in these countries, while Proton VPN Plus users get access to all servers in all countries, including Secure Core servers. See here for more details on different servers or check out our different plans.

3. Make sure that you are using a reputable client.

Make sure that you installed the correct client and have updated to the latest section.

For example, a staggering number of VPN clients (external link – CISRO research paper, PDF) available in the Android Play store are not properly implemented and pose a security risk instead of improving your privacy.

Despite a few bad implementations, a good number of reliable clients exist. If you have auth problems, please use one of our recommend clients from our guides for macOS, Linux, Android, and iOS.

4. Check whether a different server works

Connect to a different server in a different country and see if this issue persists. Sometimes, we need to take certain servers offline for maintenance and as such it can happen that they are temporarily unavailable. In the Proton VPN native applications, this information will automatically be displayed.

For third party clients, check the server page and or our status page to see if there are any reported downtimes.

5. Check number of connected devices / wait x minutes and retry

Make sure that you do not have more devices connected than your maximum number of allowed connections. Is that the laptop in the other room still connected? How about your workstation? Or that tablet at your parents’/friend’s/partner’s place still connected?

Double check your past devices and make sure that none of them are keeping their sessions alive and taking up connection slots.

6. Upgrade to Proton Plus

Our Plus plan allows up to ten connections. If you are on our Free plan, you can upgrade for more connections.

7. Change OpenVPN username and password and retry the connection

If all of the have not yielded good results, try changing your OpenVPN username and password as explained here and see if this enables you to connect again.

Warning:  This will require you to reset all other existing devices which use the OpenVPN password (native clients will adjust automatically). Example: you have Tunnelblick set up on Mac successfully but encounter issues with iOS connections. If you reset your OpenVPN credentials, both devices need to be reconfigured.

8. Get the latest OpenVPN config files

Periodically, we do update config files, and servers are sometimes removed, reassigned, or added. If none of the steps above are working for you, you can try using the OpenVPN config files for your platform.

To do this, log in to using your Proton username and password (details here) and go to DownloadsOpenVPN configuration files.

9. Check if you have paid for the services

When you register and pay for Proton VPN, you will be charged the moment you register. After the time you have paid for goes by, you will have to pay for the invoice that you will receive at the end of subscription.

To find your invoices, log in to and go to →PaymentsInvoices.

Still encountering AUTH FAILURE?

If you’ve tried all of the steps above and are still encountering authentication failure, please contact our support team and provide us with results for each of the above steps. That way we can directly pick up where you left off and continue to solve the Auth Failure and connect your to Proton VPN in a timely manner.

Related Articles

How to set up Proton VPN on Mac

How to set up Proton VPN on Linux

How to set up Proton VPN on Android

How to set up Proton VPN on iOS

Post Comment


  1. Fiona

    Hello I have just installed ProtonVPN and I want to access a site that is only available within the UK. I have set my VPN to the UK but it still will not let me access the page. Am I doing something wrong?

  2. ProtonVPN Team

    Hello Fiona, please contact our customer support team for the consultation.

  3. Matt

    New to Proton. Trying to connect and posting Authentication password but it doesn’t accept it. Simply asks for it again and again. Am I missing something?

  4. ProtonVPN Team

    Hello Matt, please make sure that you are using the OpenVPN credentials and not the ProtonVPN credentials as they are two different types of authentications.

  5. Boris

    Connect attempt results in message “Maximum connection limit reached”
    Since I’m using the FREE plan, I get this message when trying to connect to either of the two server sites I’m permitted to use.
    This trouble seemes to be the result of upgrading to ver 1.6.2. Prior to the upgrade, I have had no trouble using the FREE plan.
    Please advise.

  6. ProtonVPN Team

    Hello Boris, please contact our customer support team for detailed investigation as we need the connection logs.

  7. Jay

    There is 2 payments for 27th July 1 has been payed I don’t have 2 proton accounts…? As a result I have no VPN or email acc

  8. ProtonVPN Team

    Hello Jay, It would be the best that you would contact our customer support team via this form with your paid accounts usernames.

  9. monkeyvpn

    Hi. I am trying to use Portable OpenVPN with the server settings for ProtonVPN. If I try to use the Windows UDP or TCP settings, I get the following message:
    Options error: Unrecognized option or missing parameter(s) in block-outside-dns (2.2.2)
    Use –help for more information.
    It doesn’t even get to the sign on window.
    If I use the router UDP or TCP settings (even the iOS settings), I can get to the sign on window, but when I input my username and password, it fails to authenticate and boots me out with the following message:
    Wed Mar 28 21:14:19 2018 OpenVPN 2.2.2 Win32-MSVC++ [SSL] [LZO2] [PKCS11] built on Dec 15 2011
    Wed Mar 28 21:14:46 2018 ERROR: could not read Auth username from stdin
    Wed Mar 28 21:14:46 2018 Exiting
    Would you be able to tell me what I’m doing wrong?

  10. ProtonVPN Team

    Please contact our customer support team and we will do our best to help you out!

  11. ComodoHacker

    I’ve ran into the same issue.
    You have to upgrade your OpenVPN software. The ‘block-outside-dns’ option is supported in OpenVPN 2.4 and above.

  12. nader

    have this problem
    using Kali linux rolling


    ed Mar 14 05:24:16 2018 Restart pause, 5 second(s)
    Wed Mar 14 05:24:21 2018 WARNING: –ping should normally be used with –ping-restart or –ping-exit
    Wed Mar 14 05:24:21 2018 NOTE: the current –script-security setting may allow this configuration to call user-defined scripts
    Wed Mar 14 05:24:21 2018 TCP/UDP: Preserving recently used remote address: [AF_INET]
    Wed Mar 14 05:24:21 2018 Socket Buffers: R=[212992->212992] S=[212992->212992]
    Wed Mar 14 05:24:21 2018 UDP link local: (not bound)
    Wed Mar 14 05:24:21 2018 UDP link remote: [AF_INET]
    Wed Mar 14 05:24:21 2018 TLS: Initial packet from [AF_INET], sid=3836406c 408244fd

  13. ProtonVPN Team

    Could you please contact our support with full connection logs?

  14. Johan

    Could you please provide a ‘how to’ to setup the OpenVPN on a Chromebook/Chrome OS ?
    I have purchased protonvpn plus and it works like a charm on Android and Linux. Unfortunately I presumed it would work via the OpenVPN feature on Chromebooks too… Thanks!

  15. ProtonVPN Team

    Hello Johan,
    Could you please contact our support team, we are sure they will be able to help you out!

  16. DW

    I am senior and have to many names and way to many passwords. I like your VPN very much, L can not afford all the fees for the programs that seem to be necessary to use the Internet so I go for the free products mostly. I have 2 laptops an old win xp desktop and a new desktop so I thought that I would use your product. I do not give out info about myself very often but I like Proton VPN enough to make the exception. I would like to continue using it, but I seem to have problems signing in (not just here).If you could help it would be greatly appreciated. Thanks DW

  17. ProtonVPN


    We appreciate your interest in our services! Please contact us through the following link and we will send you an invitation, so you could easily create your ProtonVPN account:

  18. EJL

    I get the following warning when I start my vpn
    warning ; Tunnelblick could not fetch IP address information before the connection to was made.

    Also in the log book I see following warnings ;

    – NOTE: The DNS servers do not include any free public DNS servers known to Tunnelblick. This may cause DNS queries to fail or be intercepted or falsified even if they are directed through the VPN. Specify only known public DNS servers or DNS servers located on the VPN network to avoid such problems.
    -WARNING: –ping should normally be used with –ping-restart or –ping-exit

  19. ProtonVPN Team

    Hello, we cannot figure out why Tunnelblick is returning this error. Whenever you will connect to a VPN server, simply check whether your computer does leak DNS, however, DNS shouldn’t leak and if they do, please contact us via and we will check where the issue might be.

  20. Derrick Paull

    At log-in attempt, I get the message “A problem occurred while checking this computer’s apparent public IP address.”

  21. ProtonVPN


    Could you please contact us through the following link, and provide more details regarding which platform you are using as well as send us a screenshot of the error message?

  22. Jordi

    How to fix this??
    10:54 AM WARNING: this configuration may cache passwords in memory — use the auth-nocache option to prevent this

  23. ProtonVPN

    This is expected behavior and not a problem as OpenVPN credentials are not deemed sensitive and do not reveal anything about the user account (if set to a nondescript username as recommended)

  24. Edgar

    Hi!!! How to convert a “OVPN file” to a “ONC file” for Chromebook???

Comments are closed.

your internet

Get Proton VPN
Get Proton VPN

For customer support inquiries, please submit the following form for the fastest response:
Support Form

For all other inquiries:

Version: OpenPGP.js v4.10.10


You can also Tweet to us: