Upgrading to 4.2.2 error: Unexpected string in JSON at position 354

I was trying to update my website to 4.2.2 from 3.42.5 but ran into this error “unexpected string in JSON at position 354”. Any idea what I should do to solve this?

URL: insights.egomonk.com
OS: Ubuntu v18.04.5 LTS
Nod Version: v12.13.0
Ghost Version: 3.42.5
Ghost-CLI Version: 1.16.3
Environment: production