Fatal exception error

In computing, a fatal exception error or fatal error is an error that causes a program to abort and may therefore return the user to the operating system. When this happens, data that the program was processing may be lost. A fatal error is usually distinguished from a fatal system error. A fatal error occurs typically in any of the following cases:

An illegal instruction has been attempted
Invalid data or code has been accessed
An operation is not allowed in the current ring or CPU mode
A program attempts to divide by zero.

In some systems, such as macOS and Microsoft Windows, a fatal error causes the operating system to create a log entry or to save an image of the process.