typically such a message indicates that you need to have the year portion of the date using 4 digits, such as "2016". If you have this formatted this way in your listing or if you change it to this format and continue to encounter difficulty, please let us know in a support case from under the Help tab of the site which listing you are running into the issue with and we will be happy to look into it for you.
When you block a person, they can no longer invite you to a private message or post to your profile wall. Replies and comments they make will be collapsed/hidden by default. Finally, you'll never receive email notifications about content they create or likes they designate for your content.
Note: if you proceed, you will no longer be following .