when i run the sample of ImageTargetsNative , i got the error log as below:

D:\Downloads\Vuforia\android-ndk-r13b-windows-x86_64\android-ndk-r13b\build\core\prebuilt-library.mk

Error:(45) *** Android NDK: Aborting    .  Stop.

Error:Execution failed for task ':ImageTargetsNative:cleanNative'.

> Process 'command 'D:\Downloads\Vuforia\android-ndk-r13b-windows-x86_64\android-ndk-r13b/ndk-build.cmd'' finished with non-zero exit value 2

 

pls help me  help me help me !