Setup
- Retail POS for Mac or PC
- Retail POS on iPad
Answer
One of the reasons when this error shows up is when we try to update the SKU of the product with an existing product's SKU number. Each product in Retail POS requires a unique SKU, which is why you will not be able to save a new product if the SKU is already in use.
This error only comes up when updating SKU for the standard product but it does show the name of error for the variant product.