As a new seller, you need to establish a positive selling history and show that you're able to meet the needs of your customers. This is an eBay response and you will need to submit a support request to eBay directly. Hyperspace cannot resolve this for you.
If you submit a request to eBay, they would look at your file, then decide if they want to let you list more or not during the current month.
You can get this error if you are selling large quantities of items. You can also get this error if you are listing high-value items.
New sellers have listing limits, both in terms of price and quantity, mainly to protect the new sellers from themselves until they gain experience by selling lower cost items.