It appears that as of today 2026-05-29 that the Sandbox has decided that using the clientId of 'sdk-node-1.0.10' is invalid. This is the clientId that is hardcoded into the last release of https://github.com/AuthorizeNet/sdk-node
Using the exteranlConfig param on the constructor with a custom clientId makes this error message go away.
Hopefully this doesn't impact Authorize.net production before our next release, if this was communicated in advance somewhere that I've missed I would love to know.
