Xilinx SDK Error Launching Program: Error while running ps7_init method

Sometimes I get this message:

Error Launching Program

Unexpected error while launching program Error while running ps7_init method:

Typically, this happens to me after I have copied a project in ISE over to my computer or overwritten some files.

The things you should check are:

• You have the system.bit bitstream selected
• When you go to Run as> Run Configurations> Xilinx C/C++ ELF go to the Device Initialization tab, and browse/refresh the .tcl even if it is correct