Qt error: LNK1181: cannot open input file 'debug\main.obj'

Question

Qt creator was working well, but suddenly shows a problem error: LNK1181: cannot open input file \'debug\\main.obj\'.
This problem shows always with any typ

Answer 1

This problem occurs also if you have in the .pro or .pri files something like:

HEADERS += \ \

or

SOURCES += \ \