You cannot add another “%s” to your cart

Overview 

Triggered by products marked “Sold individually”.

Root Cause 

• Product setting Sold individually prevents quantity > 1 per order.

Impact 

• Customers can purchase only one unit per order.

How to Fix the Issue 

1. Merchant: Edit product → Inventory → uncheck Sold individually if multiple units should be allowed.
2. Customer: Remove existing item from cart before adding another.

Additional Notes 

• Useful for licenses/unique items.