How do I fix this?

Can you provide info about how the

kubeconfig

stack output is being created, and what's in the JSON file itself? There are a lot of reasons this could be failing. Do you know how authentication worked before (IAM authenticator, static token, etc)?

The stack output is created like this:

That does look sufficient to have authentication work. What happens when you run

AWS_PROFILE="<your profile name>" aws eks get-token --cluster <your cluster name>

, replacing the two values from the values in your JSON file?

it does print out a valid token with a valid expiration date timestamp: "expirationTimestamp": "2021-09-24T21:23:54Z"...

The only other thing I could think of is an outdated

kubectl

that doesn't understand the format of that JSON file.

I have a 1.21.3 version which is pretty new. not only kubectl doesn't work. Pulumi provider is broken as well (used to work). Not sure what the issue. Will keep digging into it. Thanks Jesse, for your help!