Command copy exited with code 4 when building - Visual Studio restart solves it

Question

Every now and then when I build my solution here (with 7 projects in it) I get the dreaded \'Command copy exited with code 4\' error, in Visual Studio 2010 Premium ed.

Answer 1

This can happen in multiple cases:

1. When the complete string path is longer than 254 chars.
2. When the name of the file to be copied is wrong.
3. When the target path is wrong.
4. When the readonly attribute is set on the copied file or target folder.