My SSD drive from my old MacBook Pro 2012 has been installed into a new MacBook Pro (also 2012). The SSD was partitioned between windows and macOS but only windows will load. I can see both in disk utility but the main partition of macOS is grayed out and it says it’s unmounted. I want to avoid a full reinstall if possible as I’m not sure everything is backed up. I’d really appreciate a solution if anyone has ideas!