Failure mode is a term for a, usually common, way things fail when attempting something. for example, confirmation bias is a common failure mode in reasoning.

Knowing and understanding possible failure modes in what you attempting to do is important in order to avoid them.

See also: Postmortems & Retrospectives

Other Examples:

Bias
Planning Fallacy
Status Quo Bias
Affect Heuristic
Aversion/Ugh Fields
Bucket Errors
Compartmentalization
Confirmation Bias
Fallacies
Goodhart's Law
Groupthink
Heuristics & Biases
Mind Projection Fallacy
Motivated Reasoning
Pica
Pitfalls of Rationality
Rationalization
Self-Deception
Sunk-Cost Fallacy
Paperclip Maximizer
Moral Mazes
Replication Crisis
Moloch
Tribalism
Simulacrum Levels
Information Hazards
Pascal's Mugging
Akrasia
Procrastination
Nonapples

Posts:
Guessing the Teacher's Password
Expecting Short Inferential Distances