So when I try to connect my Samsung 28 inch 4K Monitor to my 720p res laptop which runs ubuntu 18.04, it turns the screen black a few seconds after I put the HDMI cable in, then it comes back a few seconds after I remove it and I see this error: 
I'm not sure why, I went to Intel's website and it says my graphics card supports 4K: https://www.intel.com/content/www/us/en/embedded/products/braswell/overview.html
UPDATE: it seems to work for the Plasma KDE desktop.