Apologies if this is a duplicate, I haven't found a solution in similar questions. I'm trying to upload a docker image to Google Kubernetes Engine. I've did it successfully before, but I can't seem to find my luck this time around.

I have Google SDK set up locally with kubectl and my Google Account, which is project owner and has all required permissions. When I use

kubectl create deployment hello-app --image=gcr.io/{project-id}/hello-app:v1

I see the deployment on my GKE console, consistently crashing as it "cannot pull the image from the repository.ErrImagePull Cannot pull image '' from the registry".

It provides 4 recommendations, which I have by now triple checked:

• Check for spelling mistakes in the image names.
• Check for errors when pulling the images manually (all fine in Cloud Shell)
• Check the image pull secret settings So, based on this https://blog.container-solutions.com/using-google-container-registry-with-kubernetes, I manually added 'gcr-json-key' from a new service account with project view permissions as well as 'gcr-access-token' to kubectl default service account.
• Check the firewall for the cluster to make sure the cluster can connect to the ''. Afaik, this should not be an issue with a newly set up cluster.

The pods themselve provide the following error code:

Failed to pull image "gcr.io/{project id}/hello-app:v1": 
[rpc error: code = Unknown desc = Error response from daemon: 
Get https://gcr.io/v2/{project id}/hello-app/manifests/v1: unknown: Unable to parse json key., 
rpc error: code = Unknown desc = Error response from daemon: 
Get https://gcr.io/v2/{project id}/hello-app/manifests/v1: 
unauthorized: Not Authorized., rpc error: code = Unknown desc = Error response from daemon: 
pull access denied for gcr.io/{project id}/hello-app, 
repository does not exist or may require 'docker login': denied: 
Permission denied for "v1" from request "/v2/{project id}/hello-app/manifests/v1".]

My question now, what am I doing wrong or how can I find out why my pods can't pull my image?

Kubernetes default serviceaccount spec:

kubectl get serviceaccount -o json
{
    "apiVersion": "v1",
    "imagePullSecrets": [
        {
            "name": "gcr-json-key"
        },
        {
            "name": "gcr-access-token"
        }
    ],
    "kind": "ServiceAccount",
    "metadata": {
        "creationTimestamp": "2020-11-25T15:49:16Z",
        "name": "default",
        "namespace": "default",
        "resourceVersion": "6835",
        "selfLink": "/api/v1/namespaces/default/serviceaccounts/default",
        "uid": "436bf59a-dc6e-49ec-aab6-0dac253e2ced"
    },
    "secrets": [
        {
            "name": "default-token-5v5fb"
        }
    ]
}