Important: Please read the Qt Code of Conduct -

Qt 5.12.7 - QWebEngine Could Not load plugin

  • Hello everyone!
    I have recently update Qt from 5.12.4 to 5.12.7 and recompiled from source by myself,
    i have a webapplication that load through QtcpServer a flash application


    To recompile Qt from source i used this configure command

    configure -release -opensource -confirm-license -plugin-sql-sqlite -nomake tests -nomake examples -skip qtlocation -prefix /usr/local/Qt-5.12.7 -webengine-proprietary-codecs -webengine-pepper-plugins
    make install

    This command work fine with Qt 5.12.4 and my flash page application load correctly. (without -webengine-pepper-plugins)

    So, first i have added

    QWebEngineSettings::defaultSettings()->setAttribute(QWebEngineSettings::PluginsEnabled, true);

    and obtain the Could Not load plugin error, than i have tried a workaroung found in Qt bug tracker

    qputenv("QTWEBENGINE_CHROMIUM_FLAGS", "--enable-pepper-testing ");

    Nothing work.

    i've also found this on Qt bug report
    and they say this problem was fixed in 5.12.7, 5.14.0 RC1
    So I have checked in qt source code

    commit 41cef6e19364d785bd77c42e45ef7ca32e601410 (HEAD, tag: v5.12.7, origin/5.12.7)
    Date:   Thu Jan 16 15:22:27 2020 +0200
        Add changes file for Qt 5.12.7
        + 14e2814f95cbb1759100a2b974bc61ef39dfb9c2 Bump version
        + 5f05d9d1a3e0f30d4e7cccfe2d70387437fcccf3 Fix pepper flash plugin permission
        + 8b6f4924a1a8564987a9f0110060cc9b3a2d89bf Update Chromium
        + 7d82dafa46a356b80c8e55fda7e57f28ff1bc423 Fixup Update Chromium
        + a4b598d1633e8278776c922faae012681018cdc9 Merge remote-tracking branch 'origin/5.12.6' into 5.12
        + 5fa161b5f273ec60e77bbdcfdd0f87dd42a5a0bc Update Chromium
        + d268d9bba5589b7cc33e158b8563eae2ad67caff Update Chromium
        + 13fd53ae994ada3fca89c0d39b17df5395b712bf Update Chromium
        + 85e542f9376fd9bc8430c34b86ac05d13ed8d3f8 Update Chromium
        Change-Id: Iffa4dbd79f9bc3777c2f1a70519b8893e99c9758


    git show 5f05d9d1a3e0f30d4e7cccfe2d70387437fcccf3
    --- a/src/core/content_client_qt.cpp
    +++ b/src/core/content_client_qt.cpp
    @@ -125,7 +125,8 @@ static QString getLocalAppDataDir()
     static const int32_t kPepperFlashPermissions = ppapi::PERMISSION_DEV |
                                                    ppapi::PERMISSION_PRIVATE |
                                                    ppapi::PERMISSION_BYPASS_USER_GESTURE |
    -                                               ppapi::PERMISSION_FLASH;
    +                                               ppapi::PERMISSION_FLASH |
    +                                               ppapi::PERMISSION_SOCKET;

    it seems allright.

    as additional info: Using Qt NO recompiled works fine. (but i need proprietary codecs for webengine)
    At the moment this problem occured for mac osx, i can't buid my application for windows ( )
    there are any solution to solve this problem?
    Any other idea are welcome
    Thanks in advance

Log in to reply