Line: 1: Qt Quick emulation layer crashed.

I keep on getting this error message opening .qml files in the Designer inside Qt Creator: "Line: 1: Qt Quick emulation layer crashed."
I tried all kinds of projects, even the simplest examples that come with Qt, like objectlistmodel, and I still get the error although I can compile and run them without any problem! I tried adding Style=Desktop to qtquickcontrols2.conf file but that didn't make a difference.
I made my tests on two Windows 10 computers with Visual Studio 2019 installed. One of them had a fresh installation with only one version of Qt and Qt Creator, still had the error.
Qt Creator versions 4.11, 4.12 RC, and 4.13 beta
Qt version 5.9, 5.11.3, 5.14, and 5.15 (I have some projects requiring specific Qt versions!)