In computing, a bus error is an attempt, generally, to access memory that the computer cannot address. Bus errors can also be caused by any general device fault that the computer detects.

To the programmer, it probably indicates that the data structures are messed up somewhere, so that when the programmer thinks they're pointing at one address, they're actually pointing at another. Such confusion is much easier to generate in, say, C than in Java. It normally has to do with writing to "non-existent" memory (the object has been deallocated) or writing off the end of an array or assigning an object of larger size to an object of smaller size.

Bus errors may also be generated by a wayward debugger.

This article is a stub. You can help Wikipedia by fixing it.