Etsy have recently introduced an update to their Shpping Profiles, requiring readiness state data be sent when updating stock levels. We have released an update to support this change on Etsy's side.
If you have encountered this error, you should be able to synchronise stock between ChannelGrabber and Etsy by performing a Stock Push (navigate to Settings > Sales Channels, and switch Stock Management OFF then ON again for the Etsy channel(s)).
Some customers have reported that after doing this, the error persists for some listings. We have found that in such cases, we are receiving readiness_state_id: null from Etsy for the relevant listing(s). It seems that some listings for users might not have been migrated automatically by Etsy to the new Shipping / Delivery Profiles that they have introduced.
To resolve this, you may need to manually assign Delivery Profiles to the affected listings:
In Etsy, go to Shop Manager > Listings.
Edit the relevant listing(s) individually or in bulk, and assign a Delivery Profile to them.
Save any changes that you have made.
Once you have done this, you should be able to update stock from ChannelGrabber with a Stock Push, or alternatively delete your error Etsy listings and re-import them to update them.
Please contact our Support Team if you have any issues or questions in relation to this at all!