Failed to register with host when installing blueprint

[Juho Vainio]

I'm trying to create a custom blueprint template from the tutorial: https://developer.atlassian.com/cloud/confluence/multi-page-blueprints-with-confluence-connect/

I've set up a development confluence in the cloud and enabled the development mode there. I also have an ngrok account registered.

I've also modified the credentials.json so that the user name is admin and the password is the one I have on my Atlassian account.

I also had to modify the config.json "hosts" so that the confluence url was not ending with "confluence" but with "wiki". Then I also removed the JIRA url from the hosts config.

No other changes were made.

Node version is v8.10.0. Npm version is 5.6.0.

When I run npm install, I get an error:

Failed to register with host {some guid here}
Error: Parse Error
Error: Parse Error
    at TLSSocket.socketOnData (_http_client.js:440:20)
    at emitOne (events.js:116:13)
    at TLSSocket.emit (events.js:211:7)
    at addChunk (_stream_readable.js:263:12)
    at readableAddChunk (_stream_readable.js:250:11)
    at TLSSocket.Readable.push (_stream_readable.js:208:10)
    at TLSWrap.onread (net.js:607:20)
Failed to register with host {another guid here}
Error: Parse Error
Error: Parse Error
    at TLSSocket.socketOnData (_http_client.js:440:20)
    at emitOne (events.js:116:13)
    at TLSSocket.emit (events.js:211:7)
    at addChunk (_stream_readable.js:263:12)
    at readableAddChunk (_stream_readable.js:250:11)
    at TLSSocket.Readable.push (_stream_readable.js:208:10)
    at TLSWrap.onread (net.js:607:20)
Add-on not registered; no compatible hosts detected

Any ideas?