The lower one stopped because it caused an exception. Stopped at thread 0 Exception ...?

Question

Complete the error message in the debugger:

"The flaw was stopped because it threw an exception. Stopped in thread 0 with exception 0xfbdeba, code: 0xc0000005: read access violation at 0x0, flags = 0x0."

I can compile my code without any errors, but when I run it or debug it fails,

this error occurred when I used QMessagebox to display a message, if I comment on this message program, it works fine. I am trying to place QMessagebox in main.cpp right after initializing QApplication, the same error exists.

I can not understand what is the cause of this error ???

Please help me. I am using QT 4.8.1 with msvc 2010 compiler.

And what I'm trying to do: I'm trying to change an open source application called Open-sankore (source code is here ...) and try to check what if the user has filled out the registration form? if you don’t show the user a message.

I am adding a piece of code to the first line of UBApplication :: exec (..).

int UBApplication::exec(const QString& pFileToImport) { if(CheckLock() == -1) { QMessageBox myBox; myBox.setText("Please Complete The Registration form to continue!"); myBox.setWindowTitle("Warning!"); myBox.exec(); } 

After an error occurs, debug cursur goes to UBBoardController.h and works below

 UBBoardView* controlView() { **return mControlView;** } 

Answer 1

I found that this error most often occurs when trying to use a variable that is not initialized.

Answer 2

This error occurs when an unused object is deleted in the destructor.