用IAR下载程序时出现Fatal error: Reading CPU status failed Session a...

用IAR ，TWR-KV58F220M用OpenSDA miniUSB下载程序时出现Fatal error: Reading CPU status failed   Session aborted!
之前下载程序还是挺正常的，但突然就出现这种情况，求大神看看怎么解决
下面是下载程序是的信息：
Tue Mar 08, 2016 17:33:14: Loaded macro file: D:\Program Files (x86)\IAR Systems\Embedded Workbench 7.3\arm\config\debugger\Freescale\KV5x.dmac
Tue Mar 08, 2016 17:33:14: Loading the CMSIS-DAP driver
Tue Mar 08, 2016 17:33:14: Probe: CMSIS-DAP probe SW module ver 1.11
Tue Mar 08, 2016 17:33:14: Probe: CMSIS-DAP S/N '03300203C5591E0900000000000000000000000038A5E2C1' mapped to a number 00001.
Tue Mar 08, 2016 17:33:14: EARM v.3.96
Tue Mar 08, 2016 17:33:14: Emulation layer version 3.96
Tue Mar 08, 2016 17:33:14: Notification to core-connect hookup.
Tue Mar 08, 2016 17:33:15: CPU status - IN RESET
Tue Mar 08, 2016 17:33:15: LowLevelReset(script, delay 200)
Tue Mar 08, 2016 17:33:15: Calling reset script: ResetAndDisableWatchdog
Tue Mar 08, 2016 17:33:18: Disable watchdog ...
Tue Mar 08, 2016 17:33:18: D:\Program Files (x86)\IAR Systems\Embedded Workbench 7.3\arm\config\debugger\Freescale\KV5x.dmac(34,18): Error: Operation error.  
Tue Mar 08, 2016 17:33:18: Error while calling macro ResetAndDisableWatchdog
Tue Mar 08, 2016 17:33:23: Fatal error: Reading CPU status failed   Session aborted!
Tue Mar 08, 2016 17:33:24: Loading the CMSIS-DAP driver