@nmik I have the same issue. Same exact issue. I’m also on high sierra. I’ve been waiting for an update but the update was what broke it in the first place. I’m also using an external display and sometimes the resolution configuration is a little wonky when dragging it from display to display, I wonder if that’s part of the issue.
I had the same issue as nmik and miniluigi. Used a third-party app uninstaller to remove Plex and all related files, then reinstalled (v1.17.0.1376). Works fine now.
Given that Plex for Mac is an app that is usually used in fullscreen mode, to require users to install and use a third-party uninstaller EVERY TIME you happen to close it while it is in fullscreen mode is one hell of a bug.
Still a problem three months after the original post here. Pity no one at Plex reads these forums.
Chiming in to say that I’m having the same ridiculous issue. I only use the Plex player on this Mac, but it’s the set-top computer, and we use it to drive all of our viewing content…which has mostly shifted over to Plex. It’s been buggy for a couple of months (fullscreen mode breaking upon relaunch libraries/content sometimes inaccessible until a relaunch, and my home page customization randomly being dumped a couple of days ago), but today it finally just won’t show a window.