M1 Macbook pro external monitor issues


First time running VDMX on my new M1 MBP 16" and I’m getting strange issues with the UI’s window management and the external display. Seems like something really basic that I’m missing but I just can’t figure it out.

Basically: VDMX seems to be locked within my main display (Display 1 / “D1”) and I can’t get it to move the UI to the secondary smaller laptop screen (Display 2 / “D2”). I want to use D1 as a large full screen output monitor, with the UI controls on the smaller laptop screen (D2).

So when I boot up a project it loads up on D1. But if I try dragging a window to D2 it stops at the edge, as if no 2nd monitor exists. This happens to all windows except the Workspace Inspector and UI Inspector which are different (they’re os native?) from the other “panel” windows.

So I tried assigning VDMX to D2 (right-clicking on VDMX in the Dock), which works as expected - it moves the entire UI to D2 where I want it. But as soon as I click on one of the panels to try to adjust it, it snaps over to D1 and gets stuck within those bounds again.

I have similar issues with Premiere. I can drag one of the panels from D1 to D2 - but only after I release the mouse button. But WHILE I’m dragging and the mouse is inside D2, the ghosted window that would usually pop up as an overlay to guide you, it actually appears on D1! Definitely a bug. And when I release the mouse the panel correctly snaps to where my mouse is in D2.

So it seems like it affects both VDMX and Premiere in similar ways: regular OS-native windows move between displays just fine, it’s just the additional “proprietary” windows like premiere’s ghosted ones, or VDMX’s Panels (that aren’t native like the UI Inspector), that aren’t seeing the second display.

Hope it’s something silly I’m overlooking. Thing is I’m having other issues with premiere, that look a bit like what this guy is saying, but still different - it’s unrelated to the issues I’m describing with VDMX… …seems somewhat connected maybe?

  • OSX 12.3.1
  • VDMX

System Prefs / Display settings:

  • Screen 1 (Primary): External monitor
  • Screen 2: Laptop monitor


Hi @DT83,

Is your top menu (File, Edit, View, etc.) set on your second “primary” display? Most applications open on the screen that the menu is set to. I’m assuming you have “Displays have separate spaces” turned off under mission control in system preferences?



Hi PO!
Yeah the top menu is appearing in the primary display, which is where VDMX is loading up. “Displays have separate Spaces” is turned ON (as I need them to).

VDMX’s UI should be able to move over to my secondary display though, right?



Here’s a vid I tried to capture.

<— Secondary | Primary —>

This shows when I forced it to open VDMX in L monitor.
Clicking on a window snaps it to R monitor.



VDMX has a deliberate setting for this that sometimes turns itself on: In the Windows menu there is a menu item for “Keep Windows on main screen”. If this is checked, you are unable to move GUI elements to other screens. Uncheck it and you can place things everywhere.

See if that menu item has turned itself on, or try to turn it on then off. I have been thrown multiple times by this, it seems to happen on macOS and/or VDMX updates. Perhaps its the default when installing VDMX.



Haha yep that’s the one! New computer so it’s def a default setting, but now I remember it from years ago when I last unchecked it. Thanks so much!