看看这个错误信息是什么原因？

build target 'Target 1'
compiling FW.C...
.\FW.C(1);warning C500:MISSING DEVICE (SECURITY KEY NOT FOUND)
compiling PERIPH.C...
.\PERIPH.C(1):warning C500:MISSING DEVICE (SECURITY KEY NOT FOUND)
assembling DSCR.A51...
linking...
BL51 BANKED LINKER/LOCATER V4.14 - SN: K1U4P-L2887E
COPYRIGHT KEIL ELEKTRONIK GmbH 1987 - 2001
"FW.obj",
"PERIPH.obj",
"DSCR.obj",
"D:\Cypress\USB\Target\Lib\Ezusb\USBJmpTb.obj",
"D:\Cypress\USB\Target\Lib\Ezusb\Ezusb.ib"
To "FW"
RAMSIZE(256)
CODE( 0x4000)
XDATA( 0x5000)
*** FATAL ERROR L210:I/O ERROR ON INPUT FILE:
    EXCEPTION 0021H: PATH OR FILE NOT FOUND
    FILE:FW.obj
Target not created

我用的是cy  fx 64613，将cypress目录下的USB\Target中的FW内容copy到一个自己的目录下面，然后打开编写，只写了void TD_Init(void)中的一些初始化代码，build后出现上面的信息，不太明白为什么？