Failed to register with host

Hey Community,

I have been experiencing this error message since today in the middle of building an add-on:

Failed to register with host https://example.atlassian.net/ (200)
{
        "type": "INSTALL",
        "pingAfter": 300,
        "status": {
            "done": true,
            "statusCode": 200,
            "contentType": "application/vnd.atl.plugins.task.install.err+json",
            "subCode": "upm.pluginInstall.error.response.exception",
           ....
}
Add-on not registered; no compatible hosts detected

I did not change anything on credentials.json.
I am experiencing the same issue not only with Confluence, but also with the Jira add-on.

Any assistance would be greatly appreciated.

Kind regards,

Eunji Roh