Welcome - @Briley239 sorry you’re having issues, you could try moving from your phone to your computer to see if your getting the same error message and it’s not a servers issue. It could mean your dealing with high value item, meaning you or the other member needs to verify their phone number or ID. It also possible it’s cancelled payment lack of funds on credit card also needing verification through the mobile app. because OfferUp keeping both members safety. My best advice would be to reach out to our Customer Care teams from the link below so they can help you resolve this issue. You can also contact Customer Care through Twitter at OfferUp if this option is available to you.
OfferUp Customer care