When t during debug, this error, go to the Resources folder, open resource.qrc file with the resource editor to see if there is marked red resource file.
If you have a resource file name in red, then that it is because of the lack of the resource file, causing this error.
Correction:
1. Click the "Remove Missing Files", remove the file.
2. re-add the resource file.
OK, the error disappears.
Original link: https: //blog.csdn.net/xuxuzwl/article/details/88357859