This is a weird one.
This is a new issue on an existing Ubuntu 14.04, dual screen setup, using Unity, nothing out of the ordinary. When I go to puzzling.stackexchange.com on my left monitor screen in either chrome or firefox, that screen turns black.
This does not happen on any other website, but does happen on every page on that site (that I've tried). Going to that site in a browser on my right monitor screen doesn't have that effect. If I drag the browser from the right monitor onto the left one, the left monitor turns black once I've gotten it mostly over there. It starts showing stuff again when I drag it back.
My left screen (the one with the problem) is using an HDMI cable and the other screen is using a DVI cable.
Puzzling SE recently got a new site design, documented here. What could be going on?
lshw -c video gives:
*-display description: VGA compatible controller product: Curacao XT [Radeon R7 370 / R9 270X/370 OEM] vendor: Advanced Micro Devices, Inc. [AMD/ATI] physical id: 0 bus info: pci@0000:01:00.0 version: 00 width: 64 bits clock: 33MHz capabilities: pm pciexpress msi vga_controller bus_master cap_list rom configuration: driver=radeon latency=0 resources: irq:63 memory:e0000000-efffffff memory:f7e00000-f7e3ffff ioport:e000(size=256) memory:f7e40000-f7e5ffff
I don't know how localized this issue is to me, but since I don't know why it's happening (except that it started with the redesign), I'm reporting as per Stéphane's intstructions on the redesign:
If you see any CSS/styling bugs, please start a new post and tag it with design and bug.