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

I got the error because of this:

HEADERS += \ \
    $$PWD/QOakTreeViewRecursiveModel.h

instead of:

HEADERS += \
    $$PWD/QOakTreeViewRecursiveModel.h