Error Building the project while no code errors

Question

The errors it was working fine, it gives me the option to run the previous build which runs no problem. All i did was to add a form (win app)

Answer 1

According to the first and second lines of the error message, we can get that the copied file has been used by another process.

At this point we only need to open the task manager to close the related process, that is a magic.

Of course, you can also restart the computer to achieve the same effect.