Juce GUI Problems in EnergyXT on Yosemite

I found a weird GUI problem when I was debugging my plugin in the EnergyXT host (v2.7) on Mac OS X Yosemite 10.10.3. It also happens with the Juce Demo Plugin built from the current JUCE git tip. Whenever I close a plugin GUI window, I get a stuck borderless dark grey window on screen that will stay there until I close energyXT. The rectangle has the size of the plugin client area. When I open multiple GUIs and close one, all other instances close as well. It seems something is off with how windows get added or removed from the desktop with this host. 

Has anyone else seen this issue? Is there a workaround? Other plugins made without JUCE are not affected by the issue.

The relevant things to know here are whether this is VST or AU, and whether it's 32 or 64-bit..

Oh I'm sorry I didn't write it. This is a 32 bit VST loaded in a 32 Bit host application. AFAIK these are the only kind of plugins EnergyXT supports on OSX. 

I now saw that there is an energyXT 3 beta version. I tried that as well and I'm getting the same problem with the Juce Demo Plugin.


Ok, having had a look at this, I think it needs reporting to EnergyXT, because AFAICT it's their own window which is being left behind, not the plugin's window. This doesn't happen in any other hosts and it's not obvious why the host is failing to delete its window.

It could be that there's something we can change in JUCE that would be a workaround for this, but we'd need for info about what the host's problem is before we could know what to do about it.