The Production doesn't open when the Project inside it is opened...

Yesterday I closed the big Production that I do most of my work within, to work on a small stand-along project.

Today, I’m back to working within the main Production. From the ‘recents’ screen on startup, I selected the Project I was working in before the weekend. It opened perfectly fine, but the Production itself didn’t open. The Project opened as a stand-alone, which it’s not supposed to be, it was created inside the Production. The Production is no long in my ‘recents’ lists, so I can’t open it from that shortcut. When I go to File/Open Production/Browse and select the folder by the name of the Production I’m working in, it warns me ‘The selected folder is not a Production. Do you want to convert this folder to a Production?’.
I’m scared to do so, I don’t want to change or corrupt all the files the production was built on.

How do I get the Production open again??? How do I find the actual folder that is the Production, if the one I’m navigating to isn’t (apparently) a Production??? I’m completely lost here.