I'm getting an "Unprocessable Entity" error when updating my Shopify inventory, what does this mean?

What this usually means is the variant can't be updated at the Inventory Location you've specified in EZ Inventory.

This could happen if the specified location is no longer active or if you're trying to update the inventory in a "standard" Shopify location but the variant is configured to use a "legacy" fulfillment service location for inventory management. This error will also occur if the opposite is true, where you're updating the inventory in a "legacy" fulfillment service location but the variant's inventory is managed by Shopify.

We've talked to Shopify about this and they confirmed that to use Shopify's multi-location feature, the variant must be configured to use "Shopify" under the "Inventory managed by" field in the Shopify Admin (screenshot attached):

Shopify Admin - Shopify Multi-Location Feature - Inventory Managed By

Related info from the Shopify forums here.

App: EZ Inventory

Tags: errors, multi-location inventory, shopify multi-location