OfferUp has a long way to go to Primetime! Apparently, parsing and defining algorithms in traffic is way beyond a company that has 200+ employees and has been in business since 2011. So, the bottom line: The infamous error will continue! AND: The parrot explainations of "good standing" and "will resolve itself" and "contact Customer Care" ad infinitum.
I'm sure I'm going to get flamed for this post - but it is the truth and easily verified both online and on the numerous messages.
This error comes up when something is copied and pasted, OR when personal information is sent. It appears that you sent your name, email and phone number in a message which triggered this. Your account should be fine at this point @wildprincess.