Things were working just fine in windowed mode on my Win10 VM until it crashed and restarted. Now, resizing the Mac Parallels window no longer changes the guest resolution. I have a tiny, scaled-down Windows session and a large black area when I make the window larger. When I change the display resolution in Windows, the Mac window changes size but Windows' screen area stays the same. I have tried changing the scaling preferences in the Parallels configuration, restarting Windows, and also tried re-installing the Parallels tools with no change. It looks the same when I go to full-screen mode. I'm running Windows 10 Home under Parallels Desktop 13.3.0 for Mac Pro edition running on MacOS High Sierra v. 10.13.4 on a 13-inch 2016 Macbook Pro with an external 3440x1440 display. Here's what it looks like: What can I do to fix this?