A problem that is encountered when a program is being executed. Runtime errors can occur in software environments for many different reasons; for example, peripheral devices may not be turned on or instructions may be invalid. Such errors often occur with interpreted languages such as Java and JavaScript, which convert source code to machine language a line at a time for execution. Compiled languages will prevent some runtime errors, because the code is verified to some extent ahead of time, but resources can always be missing in a computing environment, which can cause an error upon execution. See
runtime,
runtime engine and
runtime environment.