The windows QT compilation version is invalid. It was good yesterday and cannot be compiled today. This problem also occurred before. At that time, it was solved by re-installing QT, this takes too much time. I have solved this problem again today.
Www.2cto.com I noticed that the new application was a desktop application, but now there is no desktop application. Only the Saipan device and the Harmattan program are available, indicating that the desktop application project target cannot be found.
I will go to the tool-options to view the information, as shown in: we can see that there is a red exclamation point in front of the build directory of the desktop application, which indicates that it is not found and needs to be manually added.
Then you only need to manually add the build and run directory of the desktop application, as shown in:
Www.2cto.com and then set the build and run options of your project in the project options.