Unknown Error (code: Invalid JSON response)

Thanks for reaching out @amnay70, and for sharing your Site Health information. From reviewing your Site Health information I don’t notice anything unusual with your setup that may be resulting in this notice. As REST errors are generic WordPress errors and I can see your public REST endpoints are accessible.

So we can determine more on this and ensure you can complete set up please share the following:

1. A screen recording of your experience. You can use a service such as Loom or RecordIt to share a screen recording, while using the same form previously used to share this privately. 
2. Do you see any errors or warnings before attempting set up? By that I mean errors such as “You’re site may not be ready for Site Kit…”. If so, please share any such errors.
3. Does the same occur if you don’t include Analytics as part of the setup process?

Let me know if you have any questions with the above.

@jack1972 If you’d like to open an individual support topic we can communicate with you from there. Please include any details relevant to what you’re experiencing. This may include sharing your Site Health information and a mention of whether you see this when setting up Site Kit, as per the original support topic, or elsewhere. I’ll keep an eye out for your topic. Thank you!