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

What worked for me:

1. Close the Qt Creator
2. Delete the [filename].pro.user file in your project directory
3. Open the project again and let Qt configure itself

Generally whenever I encounter an error like this, this is one of the first things I do as it solves a lot of problems with Qt.

Edit: This will of course reset your project build location.