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Fixed in 2020.1.X

Fixed in 2018.4.X, 2019.3.X



Found in










Issue ID




UnityWebRequest fails to verify certificate when "Let's Encrypt Authority X1" certificate is present in system trust store



Reproduction steps:
1. Open Certificate Manager (In Windows, search for "Manage user certificates" in the Start menu)
2. If present, delete Let's Encrypt Authority X3 certificate under "Current User\Intermediate Certification Authorities\Certificates"
3. If not present, install the Let's Encrypt Authority X1 certificate attached below
4. Open the attached project (
5. Enter Play Mode

Expected result: WebRequest is successful and data is fetched
Actual result: The error "Curl error 51: Cert verify failed: UNITYTLS_X509VERIFY_FLAG_NOT_TRUSTED" is thrown and no data is fetched

Reproduced in: 2018.4.10f1, 2018.4.16f1, 2019.2.7f2, 2019.2.19f1, 2019.3.0b4, 2019.3.0f6, 2020.1.0a4
Not reproducible in: 2017.4.36f1, 2018.4.9f1, 2019.2.7f1, 2019.3.0b3, 2020.1.0a3, 2020.1.0a11, 2020.1.0a21

Regressed in: 2018.4.10f1, 2019.2.7f1, 2019.3.0b3, 2020.1.0a4, most likely caused by Case 1076758

  1. Resolution Note (fix version 2020.1):

    Fixed in 2020.1.0a11

  2. Resolution Note (fix version 2019.3):

    Fixed in 2019.3.3f1

  3. Resolution Note (fix version 2018.4):

    Fixed in 2018.4.18f1

Comments (47)

  1. Alvarden

    May 08, 2020 17:36

    That problem still pesists on 2019.2.21f1. And apparently on other versions as well

  2. 1337pete

    May 08, 2020 15:51

    2019.2.18f1 Error shows up in console. Unity closes when I hit play. Can still build the project and run that.

  3. White_Wabbit

    May 08, 2020 15:04

    Got this in 2019.2.17f1. It just happened

  4. Malace

    May 08, 2020 14:53

    Problem still exists encountered 9:52 am. No workaround found

  5. erikpotanin

    May 08, 2020 14:52

    Hey, where can I find attached file(

  6. ANKquil

    May 08, 2020 14:44

    go offline
    go offline
    go offline
    go offline
    go offline

  7. puetsua

    May 08, 2020 14:00

    It seems everyone is getting same problem. 2018.4.22f1. Can build for iOS but Android keeps failing.

  8. nntgam

    May 08, 2020 13:52

    It same my problem at 2018.4.16f1, but at 2019.2.9f1 work normal.

  9. C00kkie

    May 08, 2020 13:37

    Got that issue today as well with 2019.2.13f1.

  10. ChrisVonMax

    May 08, 2020 13:36

    Deleting "Let's Encrypt Authority X3 certificate" does not solve the problem

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