Help Setting up Gluetun LXC with ProtonVPN

[gh2023-aesun]

I installed Gluetun via the Helper Script, and setup the /opt/gluetun-data/.env file below for ProtonVPN from information I found here

cat /opt/gluetun-data/.env
VPN_SERVICE_PROVIDER=protonvpn
VPN_TYPE=wireguard
WIREGUARD_PRIVATE_KEY=...
SERVER_COUNTRIES=United States

However, I can not clear this INVALIDARGUMENT error:

Apr 06 08:42:00 gluetun systemd[1]: gluetun.service: Main process exited, code=exited, status=2/INVALIDARGUMENT
Apr 06 08:42:00 gluetun systemd[1]: gluetun.service: Failed with result 'exit-code'.

The device status is:

systemctl status gluetun
● gluetun.service - Gluetun VPN Client
     Loaded: loaded (/etc/systemd/system/gluetun.service; enabled; preset: enabled)
     Active: activating (auto-restart) (Result: exit-code) since Mon 2026-04-06 08:47:55 EDT; 457ms ago
 Invocation: 7d58765f165a49908f58bfd1991e5347
    Process: 2821 ExecStartPre=/bin/sh -c rm -f /etc/openvpn/target.ovpn (code=exited, status=0/SUCCESS)
    Process: 2823 ExecStart=/usr/local/bin/gluetun (code=exited, status=2)
   Main PID: 2823 (code=exited, status=2)
   Mem peak: 79.9M
        CPU: 946ms

I've regenerated the wireguard key, with the same outcome.

I'm sure I'm missing something simple, so any ideas on what I can try?

[gh2023-aesun]

I've also tried double-quoting all values in /opt/gluetun-data/.env and checked that the tun is there:

ls -lah /dev/net/tun
crw-rw-rw- 1 nobody nogroup 10, 200 Apr  6 07:16 /dev/net/tun

[gh2023-aesun]

I decided to run gluetun natively and it yielded:

/usr/local/bin/gluetun 
========================================
========================================
=============== gluetun ================
========================================
=========== Made with ❤️ by ============
======= https://github.com/qdm12 =======
========================================
========================================

Running version unknown built on an unknown date (commit unknown)

🔧 Need help? ☕ Discussion? https://github.com/qdm12/gluetun/discussions/new/choose
🐛 Bug? ✨ New feature? https://github.com/qdm12/gluetun/issues/new/choose
💻 Email? quentin.mcgaw@gmail.com
💰 Help me? https://www.paypal.me/qmcgaw https://github.com/sponsors/qdm12
2026-04-06T09:23:41-04:00 WARN You are using the old environment variable USER, please consider changing it to OPENVPN_USER
2026-04-06T09:23:41-04:00 INFO [routing] default route found: interface eth0, gateway xxx.xxx.xxx.xxx, assigned IP xxx.xxx.xxx.xxx and family v4
2026-04-06T09:23:41-04:00 INFO [routing] local ethernet link found: eth0
2026-04-06T09:23:41-04:00 INFO [routing] local ipnet found: xxx.xxx.xxx.xxx/24
2026-04-06T09:23:41-04:00 INFO [routing] local ipnet found: xxxx::/64
2026-04-06T09:23:41-04:00 INFO [firewall] enabling...
2026-04-06T09:23:41-04:00 INFO [firewall] enabled successfully
2026-04-06T09:23:42-04:00 INFO [storage] merging by most recent 20901 hardcoded servers and 20901 servers read from /gluetun/servers.json
                         @@@
                         @@@@
                        @@@@@@
                       @@@@.@@                       @@@@@@@@@@
                       @@@@.@@@                   @@@@@@@@==@@@@
                      @@@.@..@@                @@@@@@@=@..==@@@@
            @@@@      @@@.@@.@@              @@@@@@===@@@@.=@@@
           @...-@@   @@@@.@@.@@@  @@@     @@@@@@=======@@@=@@@@
           @@@@@@@@  @@@.-%@.+@@@@@@@@  @@@@@%============@@@@
                     @@@.--@..@@@@.-@@@@@@@==============@@@@
              @@@@  @@@-@--@@.@@.---@@@@@==============#@@@@@
              @@@   @@@.@@-@@.@@--@@@@@===============@@@@@@
                   @@@@.@--@@@@@@@@@@================@@@@@@@
                   @@@..--@@*@@@@@@================@@@@+*@@
                   @@@.---@@.@@@@=================@@@@--@@
                  @@@-.---@@@@@@================@@@@*--@@@
                  @@@.:-#@@@@@@===============*@@@@.---@@
                  @@@.-------.@@@============@@@@@@.--@@@
                 @@@..--------:@@@=========@@@@@@@@.--@@@
                 @@@.-@@@@@@@@@@@========@@@@@  @@@.--@@
                 @@.@@@@===============@@@@@ @@@@@@---@@@@@@
                @@@@@@@==============@@@@@@@@@@@@*@---@@@@@@@@
                @@@@@@=============@@@@@ @@@...------------.*@@@
                @@@@%===========@@@@@@ @@@..------@@@@.-----.-@@@
                @@@@@@.=======@@@@@@  @@@.-------@@@@@@-.------=@@
               @@@@@@@@@===@@@@@@     @@.------@@@@   @@@@.-----@@@
               @@@==@@@=@@@@@@@      @@@.-@@@@@@@       @@@@@@@--@@
               @@@@@@@@@@@@@         @@@@@@@@                @@@@@@@
                @@@@@@@@             @@@@                       @@@@
                                                                       
2026-04-06T09:23:42-04:00 ERROR VPN settings: OpenVPN settings: password is empty
2026-04-06T09:23:42-04:00 INFO Shutdown successful

Why are these OpenVPN messages here when I was trying to configure a wireguard connection?

2026-04-06T09:23:41-04:00 WARN You are using the old environment variable USER, please consider changing it to OPENVPN_USER
2026-04-06T09:23:42-04:00 ERROR VPN settings: OpenVPN settings: password is empty

[gh2023-aesun]

I also checked that there were no spaces either side of the = in the .env file. that some others on the web have suggested.

[gh2023-aesun]

I also tried OpenVPN and ProtonVPN, with these env parameters i found here:

VPN_SERVICE_PROVIDER="protonvpn"
OPENVPN_USER="..."
OPENVPN_PASSWORD="..."
SERVER_COUNTRIES="United States"

The same warning and error occurs.