Fatal Exception

What Does Fatal Exception Mean?

A fatal exception is an error condition that indicates access to either invalid data values or illegal instructions. The invalid privilege level to an operation can also cause fatal exceptions. When a fatal exceptions occur, computers cannot continue processing program algorithms because one or more subsequent instructions rely on the variable value causing the exception.


A fatal exception is indicated by a system message that recommends that the program be closed or debugged. A user will usually close the program, whereas a developer may try to uncover the exception’s cause and rectify any coding errors.

A fatal exception may also be known as a fatal exception error.

Techopedia Explains Fatal Exception

Although a program continually communicates with a computer’s operating system, it may also need to communicate with additional running applications. This communication is achieved through several different code layers. When a layer encounters an exception, it sends that exception to the next layer, with the aim to locate an exception-handling algorithm. If a suitable algorithm is not found, the operating system sends a fatal exception error to the computer user. In some cases, fatal exceptions may result in a forced shut down of an operating system.

A fatal exception error message may also contain information that helps the developer locate the code causing the exception.


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Margaret Rouse
Technology Expert

Margaret is an award-winning technical writer and teacher known for her ability to explain complex technical subjects to a non-technical business audience. Over the past twenty years, her IT definitions have been published by Que in an encyclopedia of technology terms and cited in articles by the New York Times, Time Magazine, USA Today, ZDNet, PC Magazine, and Discovery Magazine. She joined Techopedia in 2011. Margaret's idea of a fun day is helping IT and business professionals learn to speak each other’s highly specialized languages.