To make sure sellers can deliver the level of customer service needed to succeed on eBay, all members are limited in the number of items and dollar amounts they can list. This includes active and sold items. However, if a listing ends without any sold items it won't count toward your limit.
With regard to your account specifically, you've reached your limit of 175 items or $6,500.00 for this month. You'll be able to list more next month.
You may be able to increase your limit now by confirming your information or linking your new account to an established account.