This question separates two different families of thinking abnormality. One family is Beck's cognitive errors (distortions in how a person interprets events), and the other is formal thought disorder (disturbance in the stream or form of thinking). The except answer is the term from the wrong family.
Three options are textbook cognitive distortions. Catastrophic thinking blows a situation up to its worst possible outcome. Arbitrary inference jumps to a conclusion with no supporting evidence. Overgeneralization spreads a single negative event across all of life. All three are content-level interpretation errors central to cognitive behaviour therapy.
Thought block is different in kind. It is an abrupt halt in the flow of thought, a feature of formal thought disorder classically tied to schizophrenia, not a distortion of meaning. Because it describes broken thought $form$ rather than faulty thought content, it is not a cognitive error.
So the item that does not belong among cognitive errors is thought block.
\[\boxed{Thought\ block}\]