Final answer:
The error in the sentence is a matter of tense consistency. It should be corrected to 'brought' instead of 'bring' to match the past perfect tense used earlier in the sentence.
Step-by-step explanation:
The sentence "A cold wind began to blow and Josie was glad that Uncle Anthony had insisted that they bring sweatshirts." contains an error involving tense consistency. The action of bringing sweatshirts occurred in the past, so the sentence should use the past tense form of the verb 'bring,' which is 'brought.' Therefore, the corrected sentence should read: "A cold wind began to blow and Josie was glad that Uncle Anthony had insisted that they brought sweatshirts." By making this correction, we not only correct the tense consistency, but we also create a sentence that is clear and coherent, improving the overall language used.