Hello， I run a project coded by Qt programming on visual studio 2017(on Windows 10-64bit system). The project uses some .dll files during one execution, and the project needs to be executed over and over. In this process, I use a splash screen during startup and the splash screen is not my main window. Under this condition, errors occur as follows:

[W] 14:03:38.807 [0x26EAC653890] default: ERROR: QQuickStyle::setStyle() must be called before loading QML that imports Qt Quick Controls 2.
[W] 14:03:38.815 [0x26EAC653890] default: QWindowsContext::windowsProc: No Qt Window found for event 0x1c (WM_ACTIVATEAPP), hwnd=0x0x5d0742.
[W] 14:03:38.816 [0x26EAC653890] default: QWindowsContext::windowsProc: No Qt Window found for event 0x1c (WM_ACTIVATEAPP), hwnd=0x0x32108a.
[W] 14:03:38.816 [0x26EAC653890] default: QWindowsContext::windowsProc: No Qt Window found for event 0x1c (WM_ACTIVATEAPP), hwnd=0x0xb01050.
[D] 14:03:38.943 [0x26EAC653890] default: searching for plugin folders in "F:/kysl_neuvision/build/bin/Release/plugins"
[D] 14:03:38.943 [0x26EAC653890] default: loading plugins from "F:calibrationpatternfinder"
[D] 14:03:38.944 [0x26EAC653890] default: progress: 0 message: "Loading ZIncompleteCircleGrid.dll"
[D] 14:03:38.947 [0x26EAC653890] default: progress: 0 message: "Loading ZIncompleteCircleGrid.dll"
[D] 14:03:38.947 [0x26EAC653890] default: progress: 0 message: "Loading ZIncompleteCircleGrid.dll"
[D] 14:03:38.947 [0x26EAC653890] default: progress: 0 message: "Loading ZIncompleteCircleGrid.dll"
[D] 14:03:38.948 [0x26EAC653890] default: trying to load plugin from: "F:calibrationpatternfinder/ZIncompleteCircleGrid.dll" metaData:

I'm not sure why this condition happens. Could you please give me some suggestions?Thanks.