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Fixed in 2021.1.X

Fixed in 2019.4.X, 2020.2.X



Found in




Issue ID




Freeze or crash with various stack traces when opening a project while connected to a VPN service

Shader System


How to reproduce:
1. Connect to a VPN service
2. Create or open a Unity project

Reproducible with: 2018.4.30f1, 2019.4.16f1, 2020.1.16f1, 2020.2.0b13, 2021.1.0a5
Not reproducible with: 2020.2.0b14, 2021.1.0a6

Workaround for NordVPN:
Use OpenVPN or IKEv2/IPSec to connect to NordVPN servers. Tutorials on how to do that, can be found here:

  1. Resolution Note (fix version 2021.1):

    NordVPN (and some other VPN services) seems to mess up with our network sockets based shader compiler IPC. We're moving to other IPC methods to avoid such issues.
    Fixed in 2021.1.0a6

  2. Resolution Note (fix version 2020.2):

    Fixed in version 2020.2.2f1

  3. Resolution Note (fix version 2019.4):

    Fixed in version 2019.4.20f1

Comments (35)

  1. Porocyonak

    Sep 09, 2018 22:18

    Hey guys, I was having this problem and was frustrated with manually doing everything, so I made a program to fix it!

    It basically emulates NordVPN's 'server finder' algorithm to locate the best NordVPN server, and then connects to it using OpenVPN GUI.
    It can also run on startup, so you don't have to manually connect to servers every time!

    Let me know what you think!

  2. Brad_Schneider

    Aug 24, 2018 00:51

    It's ridiculous this is even an issue... If you can't connect to servers on launch after say like 3 attempts it should just go into an offline mode, simple as that... Why the heck does it even need a connection to launch/use.

    Currently the only workaround is not use a NordVPN's app but instead use OpenVPN or routers equipped with VPN but I've yet to test this personally.

    Otherwise the workaround is don't use VPN at all when using Unity which is simply idiotic, and for some people not an option.

  3. Luix70

    Aug 09, 2018 12:42

    That's absurdity at it's most

  4. olkeencole

    Jul 10, 2018 05:06

    I am also getting this and the weirdness is all over the place.

    I turned off NordVPN, launched Unity in offline mode, re-nabled NordVPN. Now when I even try to create something like a UI element, Unity will freeze momentarily and I get the messages:

    Assertion failed: Shader Compiler Socket Exception: Terminating shader compiler process, 0 retries left
    UnityEngine.GUIUtility:ProcessEvent(Int32, IntPtr)

    Assertion failed: Shader compiler: internal error compiling shader snippet type=0 platform=4: Protocol error - failed to read correct magic number
    UnityEngine.GUIUtility:ProcessEvent(Int32, IntPtr)

    Shader error in 'UI/Default': Internal error communicating with the shader compiler process

    Failed to get socket connection from UnityShaderCompiler.exe shader compiler! D:/Program Files/Unity/Editor/Data/Tools/UnityShaderCompiler.exe
    UnityEngine.GUIUtility:ProcessEvent(Int32, IntPtr)

    Definitely not like this whole socket connection for things like the shader compiler!

    But most of the time it is the same as the original bug: Unity freezes and crashes if I have NordVPN enabled.

  5. calemb

    Jul 06, 2018 21:21

    What is more:
    1. Run Unity (with project)
    2. Then run NordVPN
    3. Force Unity to refresh (eg. change some code)

    Expected: Code is recompiling properly
    Actual: Unity freez

    Is connection really needed to recompile?

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