What is this Error and why it happened?
you can see the error in this picture :
"Your text to link here...":http://up.download.ir/di-OKTH.png
To perform Debugging, (I think) you should run it in "Debug" mode instead of "Release" mode.
You obviously did not build your application with debug symbols, which is a good idea for deploying your application to users. That's because users usually don't need debug symbols and, for proprietary software, you probably don't want them to get debug symbols. But for debugging purposes, you obviously need debug symbols - at least if you want to get useful stack traces, set break points, etc. That's why you got the warning!