For example, you have noticed, that Season Pass child is available in the checkout but Season Pass adult is not. Don't worry! This usually can be fixed very quickly.
1. Check that the product is enabled
Go to your product overview and double check that the product is enabled:
2. Check validity & visibility settings
Go to the product validity settings and make sure that visibility starts from today or earlier and validity is correct.
3. Check inventory
Is your inventory not unlimited? Go to the inventory pool and check that the capacity is larger than 0 and there are no inventory rules with 0 capacity.
If needed, increase the capacity and/or delete inventory rule.
4. Check barcode pools
Are your barcodes not generated? Go to the barcode pool and check that there are more than 0 barcodes in the pool.
For example, in the case below, additional barcodes need to be uploaded in order for the product to appear in the checkout.