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

I got this error because the user account that TFS Build Service was running under did not have permissions to write to the destination folder. Right-click on the folder-->Properties-->Security.