Yearn, a DeFi platform, has suffered a significant loss after mistakenly swapping all of its lp-yCRVv2 tokens for yvDAI. The platform has requested that those who profited from the mistake return the funds. Yearn has acknowledged that the mistake was caused by a logical error in the script used to swap tokens, which lacked sufficient output checks. The losses incurred by Yearn's treasury amount to approximately 63%.