id,summary,reporter,owner,description,type,status,component,version,resolution,keywords,cc,guest,host 15707,Video corruption with Unscaled HiDPI Output - grey rectangles cover updated regions & follow mouse,Andrew Daugherity,,"This is a regression with 5.1.2 that did not occur with 5.0.26. Host is VirtualBox 5.1.2 on OS X 10.11.6, iMac Retina 5K late 2015. With ""Unscaled HiDPI output"" enabled, the areas of the screen being updated are overwritten with grey rectangles. On a Windows 10 guest, this follows the mouse pointer (see video), as well as creating larger grey rectangles in updated fields. On an Ubuntu 16.04 guest, I see this on the login screen, but not very much within the desktop. However on the text console (Ctrl+Alt+F1) any typing or cursor movement is replaced by grey rectangles. For both guests, minimizing the VM window and unminimzing it will temporarily restore the screen, until something else is updated, as will clicking the close button to bring up the save state/ACPI shutdown/force off menu, which dims the guest window while the menu is up, and also temporarily ""fixes"" the screen. Both guests have the 5.1.2 guest additions installed. This behavior is not affected by enabling/disabling 3D support or 2D video acceleration (it happens whenever Unscaled HiDPI is enabled, regardless of 3D or 2D accel settings, although due to #14349/#14231, I have to disable 3D in the Windows 10 guest to use HiDPI; that was reported for 5.0.x and is still a problem in 5.1.2).",defect,closed,other,VirtualBox 5.1.2,fixed,hidpi,,all,Mac OS X