Trying to debug the generic 422 error

Does anybody know what message:'422 INVALID_TYPE (details: {"locale":null})' means?

All I need to do is one POST to an endpoint to update a model with a handful of simple fields and one array of repeated items (modular). I have given up trying to use the HTTP API and now switched to using the JS client. I am following https://www.datocms.com/docs/content-management-api/resources/item/create#add-a-modular-content but still getting ambiguous errors. None of the fields in the model has localisation enabled and nor can I find any documentation that says how to force a local.

Looks like you have a localised field that you need to update?

Please double check the following example: https://www.datocms.com/docs/content-management-api/resources/item/create#localising-content that is dealing with modular contents in a localised field.

If that doesn’t help, can you please share a snippet of your code so that I can have a look?

Thank you!