探索板，下载emwin历程失败

Watmin

探索者开发板，可以下载普通历程，但下载一些emwin程序的时候提示如下信息：JLink info:
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DLL: V4.80g, compiled Feb 13 2014 20:50:02
Firmware: J-Link ARM V8 compiled Nov 25 2013 19:20:08
Hardware: V8.00
S/N : 286370559
Feature(s) : RDI,FlashDL,FlashBP,JFlash

* JLink Info: Found SWD-DP with ID 0x2BA01477
* JLink Info: Found SWD-DP with ID 0x2BA01477
* JLink Info: Found Cortex-M4 r0p1, Little endian.
* JLink Info: FPUnit: 6 code (BP) slots and 2 literal slots
* JLink Info: TPIU fitted.
* JLink Info: ETM fitted.
ROMTableAddr = 0xE00FF003

Target info:
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Device: STM32F407ZG
VTarget = 3.267V
State of Pins:
TCK: 0, TDI: 1, TDO: 1, TMS: 1, TRES: 1, TRST: 1
Hardware-Breakpoints: 6
Software-Breakpoints: 8192
Watchpoints:          4
JTAG speed: 500 kHz

Erase Failed!
Error: Flash Download failed  -  "Cortex-M4"


下载emwin程序有什么需要注意的地方吗？