"Project Key is not associated with current project" trying to set up Marketplace SDK

Question

I'm trying to publish a Google Docs addon, visible only to my Google Apps domain, and then automatically install it for everyone in the domain

I have:

1. made a script in Google Drive, shared it with everyone on the domain
2. deployed it to the Developer Dashboard using Publish -> Deploy as Addon, with Publish in Google Apps Marketplace turned OFF
3. pushed it from the Developer Dashboard, making it visible just to users of my domain, giving it all the necessary fields and images
4. verified that others from the domain can install the addon by going to Addons -> Get addons in a Google Doc, toggling the filter to For mydomain.com. Also verified that it works when installed that way.
5. created a new project in Google Developers Console, added Google Marketplace SDK and created an OAuth2 client id

I'm stuck on the step of "configure Marketplace SDK", specifically the project key for the Docs add-on extension option in it, where I'm consistently getting a Project Key is not associated with current project. error.

I believe I need to finish this step, so that I could then re-do step 2 with Publish in Google Apps Marketplace turned ON, and then finally enable it for everyone.

Steps that shouldn't affect things, but might be worth noting:

• I am not the owner/admin of the domain, but the admin is assisting in steps where I get stuck. (like creating the OAuth2 client id)

• I have transferred ownership of the Developer Dashboard entry to a group that I'm owner of (on the desired domain)

• I have transferred ownership of the Developer Console project to that same group

Answer 1

the problem was I manually created a project in Google Developers Console

instead, I should've used the Resources -> Advanced Google Services -> Google Developers Console link to access a HIDDEN PROJECT (?!) and enable Marketplace SDK there.

sigh.