win8 texturepacker cannot load the frame image

I generate a big image and a plist file with the TexturePacker,then I call the funciotn :testsprite = CCSprite::spriteWithSpriteFrameName(“10.png”); 10.png is a small image in the big image.but the editor tells me that it cannot find the image~plz tell me why~

this is the error info:
Program: …-win8-2b5ec6e\Debug\HelloWorld\AppX\HelloWorld.exe
File: d:2010project\lihex-cocos2dx-win8-2b5….cpp
Line: 177

Expression: pFrame != 0

For information on how your program can cause an assertion
failure, see the Visual C++ documentation on asserts

(Press Retry to debug the application - JIT must be enabled)