"Changes cannot be applied" error on Manjaro GNOME

[salvoc81]

Although the settings interface correctly shows the scaling options, when clicking one of the options on the top of the settings window the following error message appears:

Changes cannot be applied. This could be due to hardware limitations.

I am using a MacBook retina late 2016.
video drivers: free
connection: thunderbotl -> displayport

Thanks a lot for developing the tool.

[puxplaying]

Hi and thanks for reporting the issue.
I'm still struggling to reproduce your issue because of the specific hardware constellation you use.

In my opinion it would be best to test it also directly with Ubuntu Gnome since the patch is coming from Ubuntu. In case the issue is reproducible we could file a bug report over there. And also they may have the right hardware to test it ;)

[thomasdangl]

Same issue here on arch with a Nvidia GP104 using two display port connections.
I'm however using the proprietary drivers (440.44-7).

Screen 0: minimum 8 x 8, current 6400 x 2160, maximum 32767 x 32767
DVI-D-0 disconnected (normal left inverted right x axis y axis)
HDMI-0 disconnected (normal left inverted right x axis y axis)
DP-0 connected primary 2560x1440+0+176 (normal left inverted right x axis y axis) 598mm x 336mm
2560x1440 59.95 + 165.00* 144.00 120.00 99.95 84.98 23.97
1024x768 60.00
800x600 60.32
640x480 59.94
DP-1 disconnected (normal left inverted right x axis y axis)
DP-2 connected 3840x2160+2560+0 (normal left inverted right x axis y axis) 600mm x 340mm
3840x2160 60.00*+ 30.00
2560x1440 59.95
1920x1080 60.00 59.94
1600x900 60.00
1280x1024 60.02
1280x800 59.81
1280x720 60.00 59.94
1152x864 59.96
1024x768 60.00
800x600 60.32
720x480 59.94
640x480 59.94 59.93
DP-3 disconnected (normal left inverted right x axis y axis)
DP-4 disconnected (normal left inverted right x axis y axis)
DP-5 disconnected (normal left inverted right x axis y axis)

[thomasdangl]

It turns out this is unrelated to both the ubuntu patch and your port.
In fact it is a bug in the upstream gnome-control-center GUI that is unpatched for over a year...
https://gitlab.gnome.org/GNOME/gnome-control-center/issues/247

[puxplaying]

It turns out this is unrelated to both the ubuntu patch and your port.
In fact it is a bug in the upstream gnome-control-center GUI that is unpatched for over a year...
https://gitlab.gnome.org/GNOME/gnome-control-center/issues/247

Thanks a lot for your findings @thomasdangl
So now I understand why I was unable to reproduce the issue.
Can you confirm that moving the monitors together fixes this as described in the bug report?

[thomasdangl]

Moving the monitors together in the GUI or changing their position in the X configuration has no effect, the configuration tool still refuses to apply the changes.
I'm currently trying to edit the configuration file directly instead of using the GUI.
It might be however be helpful to report this bug to the ubuntu / gnome guys as this issue makes the feature basically unusable for novice users.

Edit: I can confirm that setting the scale property directly in ~/.config/monitors.xml bypasses the shortcoming of the otherwise great configuration tool.

[puxplaying]

Turns out Ubuntu is aware of this problem
https://bugs.launchpad.net/ubuntu/+source/gnome-control-center/+bug/1800690

They also reference to the same upstream bug-report

[NovaViper]

I think this might be fixed.. it works fine on my Manjaro Gnome setup. My laptop's a Lenovo ThinkPad L390 Yoga with the free display drivers

[xyx2333]

Moving the monitors together in the GUI or changing their position in the X configuration has no effect, the configuration tool still refuses to apply the changes. I'm currently trying to edit the configuration file directly instead of using the GUI. It might be however be helpful to report this bug to the ubuntu / gnome guys as this issue makes the feature basically unusable for novice users.

Edit: I can confirm that setting the scale property directly in ~/.config/monitors.xml bypasses the shortcoming of the otherwise great configuration tool.

Could you fix it perfectly?
I tried to change monitors.xml scale but it not work. What should I do next?
Help me, please...

[jarrard]

Yeah I don't think this is fixed at all.
Using a fedora based disto Nobara and it won't tolerate scaling options when a second monitor is enabled.

Could use XRender to do it I guess but not sure how well that will work out. Also limited to XORG. (not that Wayland is anywhere near ready yet..)

[tpbnick]

Same issue for me. Manjaro Gnome + Nvidia with 3 monitors.

[Lassebq]

Config not applicable: GDBus.Error:org.freedesktop.DBus.Error.InvalidArgs: Logical monitors not adjacent
Getting this error for any non 100% scale when multiple monitors are enabled. Their scale is set to the same value and visually they appear to be adjacent in the settings preview. Is it just not possible to use fractional scaling with multiple displays? I know xrandr can, but when I tried it it led to unexpected behavior and straight up crashed entire DE.

[puxplaying]

Is it just not possible to use fractional scaling with multiple displays?

It is possible as noted in the README, take a look at: https://github.com/puxplaying/gnome-control-center-x11-scaling
This bug is about a specific multi monitor arrangement which g-c-c refuses to apply.

[Lassebq]

Is it just not possible to use fractional scaling with multiple displays?

It is possible as noted in the README, take a look at: https://github.com/puxplaying/gnome-control-center-x11-scaling This bug is about a specific multi monitor arrangement which g-c-c refuses to apply.

Unfortunately it's not possible to use patched gnome control center currently
puxplaying/gnome-control-center-x11-scaling#10

[puxplaying]

Unfortunately it's not possible to use patched gnome control center currently

This should be fixed now.