Executable file does not exist

[ChrisW67]

Did you do a complete rebuild of your project from source, using Qt5 tools, after cleaning out all the old intermediate files?

PS: For porting 4.8.5 to 5.2 i just
- .pro file: Adding
CONFIG += qt
QT += core guia

You almost certainly need:

QT += widgets

QT += widgets

To copy to clipboard, switch view to plain text mode 

not "CONFIG += qt", and probably also need to define TARGET which is often missing in Qt4 PRO files. This leads me to suspect you have not done a clean rebuild of your program.

- ui_ header file: replace QtGui by QtWidget
remove: QApplication::UnicodeUTF8

You should not be modifying the ui*.h files at all. These are generated from your Designer form *.ui file during build.