Can't get into the piano roll by double-clicking?

I just upgraded to 4.52 and suddenly I'm unable to open a piano roll by double clicking on a MIDI item. Nothing happens. Did something change about this feature, am I just dumb? This kind of matters because there doesn't seem to be any other way I know of to get to the piano roll.

Here's a video of what I'm talking about:

Perhaps you pushed it off screen. Try 'View->Cascade all floating windows after trying to open the ME.

Jesus Christ that was it. LOL Thank you so much, hahaha. I have no idea where it could've been lurking as I'd minimized both the mixer and the track window, but it showed up when I did that.