bug; software bug; glitch
Common computing term for a defect or error in software or hardware.
This app still has a lot of bugs.
A bug occurred after the update.
It took time to fix the bug.
The developer fixed the bug right away.
The tester found a new bug.
Pressing that button can sometimes trigger a bug.
バグパイプ (bagpipe, a musical instrument) sounds similar to バグ but has no relation to software errors.
バグ refers to a flaw in a program's code itself, while エラー is the malfunction or message that results when that flaw (or another problem) occurs.
Borrowed from English 'bug', originally meaning a small insect, later extended to mechanical and software defects.