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QTDesigner Plugin dll Unloaded Immediately after Loading



  • Forgive me if this is the wrong forum, I am new here.

    I am running QTDesigner 5.12.2 on Windows 10. We've been developing our own Plugins for several years now currently using QTCreator 4.8.2. Suddenly, and only on my development machine, when a new compiled dll is installed in the \Qt\Qt5.12.2\5.12.2\msvc2015_64\plugins\designer directory I get an error in the Help->About Plugins menu "Cannot load library <path to my dll>: The specified module could not be found." And none of the Widgets we've developed are accessible to me.

    I attached a debugger and have run it through Visual Studio. Upon startup I am seeing:
    'designer.exe' (Win32): Loaded <path to my dll>. Symbols loaded.
    'designer.exe' (Win32): Unloaded <path to my dll>
    Cannot load library <path to my dll>: The specified module could not be found.
    QLibraryPrivate::loadPlugin failed on "<path to my dll>" : "Cannot load library <path to my dll>: The specified module could not be found."

    I haven't a clue why this would only happen on my machine or what to look for that could be going wrong.


  • Lifetime Qt Champion

    Maybe a dependency is missing so the dll can not be loaded -> use Dependency Walker to see what dependencies you're missing.