Resolution/Fullscreen 4k display at Windows 10 *DPI issue*

[Osa]

I have a 4K display and play games at 1080p, but the fullscreen doesn't work, no resolution work with fullscreen. Only nativ 4K works, everything lower not.

Fund some errors at the log, not sure if it helps you:

closest width=1366 freq=30
closest width=1920 freq=60
1484327900206 OpenGL version: 4.5.13464 Compatibility Profile Context 21.19.407.0
1484327900206 Desktop resolution 3840x2160
1484327900207 Initial resolution 1920x1080 fullScreen=true
OpenGL 1.5 buffer objects supported
Jan 13, 2017 6:18:22 PM java.util.prefs.WindowsPreferences <init>
WARNING: Could not open/create prefs root node Software\JavaSoft\Prefs at root 0x80000002. Windows RegCreateKeyEx(...) returned error code 5.

AngelCodeFont failed to load page 0 texture C:/Program Files (x86)/Steam/steamapps/common/ProjectZomboid/media/fonts/zomboidDialogue.bmfc_0.png
AngelCodeFont failed to load page 0 texture C:/Program Files (x86)/Steam/steamapps/common/ProjectZomboid/media/font/test_0.tga
AngelCodeFont failed to load page 1 texture C:/Program Files (x86)/Steam/steamapps/common/ProjectZomboid/media/font/test_1.tga
AngelCodeFont failed to load page 2 texture C:/Program Files (x86)/Steam/steamapps/common/ProjectZomboid/media/font/test_2.tga
AngelCodeFont failed to load page 0 texture C:/Program Files (x86)/Steam/steamapps/common/ProjectZomboid/media/font/test_0.tga
AngelCodeFont failed to load page 1 texture C:/Program Files (x86)/Steam/steamapps/common/ProjectZomboid/media/font/test_1.tga
AngelCodeFont failed to load page 2 texture C:/Program Files (x86)/Steam/steamapps/common/ProjectZomboid/media/font/test_2.tga

[Osa]

It seams the game try to make the fullscreen but don't make it right. See the screenshot: https://picload.org/image/rorggcgo/snip_20170113191140.jpg
Borderless window is the same, nothing change
Did you need more?

[Osa]

I know now that's the issue is, it's the DPI scaling from Windows 10! There is a tool called "XPExplorer - Windows 10 DPI Fix", you can change the scaling back to the old Windows 8.1 and now the game runs in fullscreen with the same settings at 1080p on my 4k display.

It seams Microsoft know about the issue, but there is no fix from Microsoft. Maybe another people have the same problems or will have in the future and this can help.^^

This is the website with the tool: http://windows10_dpi_blurry_fix.xpexplorer.com/
There is also a version 2.2 which supports 4k on http://www.softpedia.com/get/Desktop-Enhancements/Other-Desktop-Enhancements/Windows-10-DPI-Fix.shtml#download