使用Qt 5.15和VS 2019时我遇到相同的问题。但是，仅当我的应用程序部署在网络驱动器上时，才会出现此问题。同一文件集合（其中qt5Core.dll位于同一文件夹中）在所有本地驱动器上都可以正常工作。

I have the same issue using Qt 5.15 and VS 2019. However, the problem only occurs when my application is deployed on a network drive. The same collection of files, where qt5Core.dll is in the same folder, works fine on all local drives.