Loading “external library” get “I/O error” in mac

I just discovered the "external library" in extendscript. So I opened up the "samplelib" example in Xcode 5, update the base sdk to 10.9 and buit it(the project file is very old, it's for xcode 2.4 and mac os x 10.4). There was no error in the building process. But, when I tried to run the script, I keep getting the "I/O error" at line "var sampleLib = new ExternalObject("lib:" + libPath);" . I tried to change the "SampleLib.framework" file to readable and writable for every user, but it didn't help.

So, guys, any idea what I've been doing wrong?

Thanks!!!