This error is coming directly from eBay:
What does it mean?
eBay have updated the return policy requirements and it may be that a certain detail within your Business Policies is not up to date.
You can check out the policy requirements right here:
eBay US: https://pages.ebay.com/seller-center/seller-updates/2018-spring/simplified-returns.html
eBay UK: https://sellercentre.ebay.co.uk/business/news/spring2018/enhanced-returns
What needs to be done?
Please go to your Business Policies on eBay and update the return policy to comply with the new eBay requirements.
For eBay US, you can manage the policies via this link:
Once you have successfully done that, simply go back into CrazyLister and Sync from eBay. You will then be able to update your listings again!
If you have any more questions, you can search our Help Center or, click on the chat tool in the bottom right corner and we'll be happy to help!