I've been searching for solutions to this problem on-and-off for about four months now, with no success. I think it's time I turn to StackExchange for input.

I run a dualboot with Windows 8.1 and Ubuntu 14.10 (x86_64) with the i3 window manager, and, seemingly at random, feh will either work, or not work, with fullscreen mode (hitting v triggers fullscreen). By "not work", I mean it will not react to any keystrokes, until I kill it with ^C, and am met with the following error message:

braden@braden-Aspire-XC-603G:~$ feh Pictures/img.png 
feh WARNING: Window Manager does not support MWM hints. To get a borderless window I have to bypass your wm.

Yet on other startups, it sometimes works. Sometimes it works, sometimes it doesn't. It seems to work consistently if I boot with an alternate kernel, but I don't think booting with an older kernel is an optimal choice here.

Clearly, i3 supports mwm hints, otherwise feh's fullscreen mode would work 0% of the time, so how can I go about forcing feh to work in fullscreen?

If I can't get it to consistently work with mwm hints, can I force feh to at least accept keystrokes in fullscreen mode?

Any ideas?

  • Oh yeah, and my feh is up-to-date. So is everything else on my system. 0 upgraded, 0 newly installed, 0 to remove and 0 not upgraded – Braden Best Jan 23 '15 at 16:56
  • As of changes to the software that I use (lightdm -> nothing, i3 -> dwm, feh -> sxiv), this doesn't seem to be a problem any more. sxiv simply refuses to enter fullscreen if it can't find mwm hints, but dwm seems to do a damn good job with mwm hints. I'm still using the same system and have not needed to perform the "network trick" to gain access to mwm hints. I believe the lack of mwm stability is a bug in i3. – Braden Best Jul 28 '15 at 19:19


On the log in screen, disconnect from the network, then re-connect. There should be a notification bubble showing up to inform you that you are connected.

After logging in, the MWM hints work without a hitch. I suspect this has to do with X's internal networking infrastructure.


  • That this solution works for:
    • Tiling window managers other than i3.
    • Systems other than Ubuntu 14.10
    • Systems running Desktop Managers other than Ubuntu's version of lightdm
    • 32-bit systems
    • Systems connected via WiFi
    • Systems not on a network


  • Contrary to what the question says, alternating between different kernels does not actually affect whether MWM hints work correctly. Through many tests, I've confirmed that there is no correlation between the kernel version loaded and whether MWM hints decided to work

  • So far, getting the "connected to network" message in the lightdm login screen seems to always coincide with MWM hints working post login. This has been tested fairly rigorously, and is the currently accepted solution.

    • This would imply a correlation between the network controller and MWM hints. Which could make sense, considering that MWM hints deal with Window Managers, which in turn deal with Xorg, which is a display server that uses the network infrastructure to send messages around.


  • I have recently removed lightdm from /etc/init.d (as well as its .conf file), switched to dwm, and changed my image viewer to sxiv. I've also added myself to some additional groups in /etc/group. As of these changes, I've noticed that I no longer have to do the above "network trick" to gain access to mwm hints, and both feh and sxiv work just fine. Wherever the problem was, I squashed it.

In other words, the problem appears to lie in either lightdm or i3.

  • I made this community wiki so anyone can edit it with new information. – Braden Best Feb 4 '15 at 17:16

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