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Fixed in 2019.3



Found in




Issue ID




[WebGL] Using XElement.Load(string uri) causes an uncaught abort exception when using dlopen() dynamic linking in Emscripten



How to reproduce:
1. Extract the user's attached "" archive
2. Open "index.html" in a browser
3. Observe the error thrown by the browser

Expected result: the WebGL build runs without throwing an exception
Actual result: an exception is thrown indicating that Emscripten's linking support is needed to use dlopen()

Reproducible with: 2019.2.0f1
Not reproducible with: 2018.4.12f1
Could not test with: 2017.4.33f1, 2019.2.1f1, 2019.2.10f1, 2019.3.0b8, 2020.1.0a9

Note: could not test on 2017.4.33f1 due to an immediate crash upon launching the project. Could not test on versions 2019.2.0a1 through 2019.2.0b10 due to various Console errors. Not reproducible on versions 2019.2.1f1 through 2019.2.10f1 and on the 2019.3 and 2020.1 streams due to the built project not loading (no error is thrown, either).

  1. Response avatar

    Resolution Note (fix version 2020.1):

    The issue described in the original report appears when using XElement.Load(string uri) in WebGL build. XElement.Load(string uri) internally a calls System.Net.WebProxy.CreateDefaultProxy, which performs MacOS platform check. This MacOS platform check has been broken in WebGL around 2018.3, causing the mentioned "dlopen()" runtime error. The issue has been fixed in 2020.1.0a19 and the fix has been backported to 2019.3.0f6.

    Note that even though the original issue has been fixed, XElement.Load(string uri) still can not work properly on WebGL. XElement.Load(string uri) relies on xml file being loaded synchronously from the web and therefore internally uses multi-threading functionality which is currently not supported on WebGL. Downloading a file synchronously without multi-threading is also not supported in WebGL because synchronous XMLHttpRequest is currently in a deprecation state. The workaround would be to download the xml file in advance (i.e. using UnityWebRequest) and then parse it directly from the string using XElement.Load(System.IO.TextReader textReader). This workaround also doesn't involve any MacOS platform checks which originally caused the mentioned "dlopen()" error.

Comments (13)

  1. 5dedb1fd4ac0930b93b0b3d56f85355c?d=mm


    Jun 11, 2020 18:40

    Experiencing issue with 2019.37f1, 2019.4.0f1 still not fixed

  2. C892c835de4f801cd8e6402be41755e1?d=mm


    Jun 05, 2020 08:44

    Reproduced on:

    EditorVersion: 2019.3.15f1
    Windows NT 10.0; Firefox 78.0b2 (64-bit)

  3. D7940162f34a7b9172c8f321e00faca9?d=mm


    Jun 03, 2020 15:32

    This is still not fixed as of 2019.3.15 even though it says fixed in 2019.3 (and still says active also? That's weird). 2019.3.14 had this listed as a known issue in the patch notes, yet it was removed in 2019.3.15 patch notes but not fixed!

  4. Da83ee21156db81ca1855df60f8b85ec?d=mm


    May 22, 2020 16:23

    This is also broken for me (2019.3.14f1).

  5. B48f59299c49c9ed6ef6e20e437a1fde?d=mm


    May 15, 2020 21:13

    Some help with this would be nice. Is happening when I use LZ4 compression in MessagePack.

  6. 82832070512fd971a3152b567d38b9e2?d=mm


    May 13, 2020 20:49

    Having this issue in 2019.3.12f1.

  7. 08d8bd932398a5b1819be61fb7d6b033?d=mm


    May 08, 2020 17:45

    Hey Unity,

    Can you fix this in 2019.3.x? I'm stuck, if I used 2019.x I get DLOPEN error, if I used 2020.x I get UnityLoader undefined error in my web build :/

  8. 4bac41b25dbd8bfcf256a376a98f42f1?d=mm


    May 04, 2020 10:48

    Please fix this? This is causing me to have to stay on an older version of Unity.

  9. F8cb409c80c848271f046e142da7ccb8?d=mm


    Apr 29, 2020 02:01

    Encountering issue on Unity 2019.3.8f1 when attempting to load webGL on Chrome.

  10. 515fd34d93a90c0257612e4b96a81a0f?d=mm


    Apr 06, 2020 14:14

    Experiencing same issue in 2019.3.0f6.

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