Verifying All Product Options Have SKUs
The first thing you need to do is make sure that all of your products with options have SKUs for each variant. When you edit a product and go to the Options & SKUs tab, you will see a SKUs tab on the left. Click on that tab and you should see SKUs listed for each of that product’s options. For example, if a product comes in Small, Medium and Large, you will see each of those options listed with an associated SKU. If the product has size AND color, you should see a SKU for each color/size combination.
You can also do an export of all your products and review every product with an assigned option set. Below the product name, you should see separate rows for each option and their associated SKU. If a product has an option set but no options/SKUs listed below, make a note of it and then generate SKUs for those products. You can generate SKUs in the Options & SKUs tab by clicking the Generate SKUs button. If that doesn’t work, you can manually create SKUs for each options or option combination.
Remember, any options without SKUs will not be migrated to V3 and you will need to manually recreate them at the end of this process.