Your Shopify store is currently unavailable
Your store could become unavailable if you were using a free trial (without selecting a payment plan), and it has expired. There may also be other reasons associated with Shopify.
Log in to your Shopify account to check what is the status of the store. If you were using a free trial, proceed by picking a Shopify payment plan and adding a payment method.
If you had already picked a Shopify plan and added a payment method, and yet the store appears to be unavailable, reach out to Shopify support for further assistance.
There is an issue with your store connection
Reconnect your Shopify store to Printify by following these steps:
Log in to your Printify account.
Go to <your-store>.myshopify.com/admin/ and log in to your Shopify account.
Navigate to “Apps” → “Customize your store” in Shopify.
Find the Printify app, and click “Add app”.
After that, you will be redirected to your Printify account.
Try to republish a product.
If you use these steps to reconnect the store, your already published products won't be unpublished.
Your daily variant publishing limit has been exceeded
Once your store reaches a total of 50,000 published variants, a rate limit takes effect. Once it does, there is a limit of 1000 variants created per day. This can result in a failed publishing attempt on Printify side in case the product happens to exceed this amount of variants.
In order to get rid of this limit, you can upgrade to the Shopify plus plan.