Wikipedia defines the fundamental attribution error this way. "The fundamental attribution error, also known as the correspondence bias or attribution effect, is the tendency for people to place an undue emphasis on internal characteristics (personality) to explain someone else's behavior in a given situation rather than considering the situations external factors" The effect has been described as "the tendency to believe that what people do reflects who they are."
Have you ever been accused of doing something for reasons that are untrue? How did it feel? Especially when your motives were honorable but seen as dishonorable by others. Those who characterize your actions or behavior as bad and, therefore, see you as a problem are guilty of the fundamental attribution error. You probably had good reasons for doing what you did.
It is a funny thing that we tend to see our motives as good and responsible but often see the motives of others as suspect and reflective of character flaws. This creates conflict, ill will, and a lack of cooperation since we have translated their actions into false ill motives. If we assumed that the motives of others were as honorable as ours, we would avoid a biased reaction against them.
What we really ought to do is give one another a break. Assume the best until you have evidence of the contrary. It would solve a lot of relational problems all around.
See also: Dangerous and hurtful assumptions