The readiness check is currently bugging me a lot.
The only error I have to resolve is this:
Command “update” failed: Loading composer repositories with package information
The “https://repo.magento.com/packages.json” file could not be downloaded: SSL operation failed with code 1. OpenSSL Error messages:
error:14090086:SSL routines:ssl3_get_server_certificate:certificate verify failed
Failed to enable crypto
failed to open stream: operation failed
Currently running: TLS 1.2 with ssl 3.1
Cannot change this due to shared hosting.