Created attachment 7901 panel settings Under certain unknown circumstances, the panel's window buttons to stop updating properly. When this happens: - Previously opened windows are still displayed, their buttons work correctly, even right-click menus work - Newly opened windows are not shown at all - Closed windows disappear, but will leave an empty space where the button used to be Under equally mysterious circumstances, the panel usually starts working again after a while. I have yet to determine which triggers bug/unbug the panel. I suspect that it has to do with changing monitor layouts and adding/removing monitors - although the bug does not trigger instantly after doing so.
Maybe related to bugs #14242, #12463, #10725. Start panel from terminal or look in .xsession-errors/xorg-session.log for error messages.
Thanks, Andrew. I managed to trigger this bug again today. It's not related to having multiple monitors, it happened after login with only the main monitor active. The only usual log entries I see are: (xfce4-panel:21234): Gtk-CRITICAL **: gtk_widget_destroy: assertion 'GTK_IS_WIDGET (widget)' failed (wrapper-2.0:21239): Gtk-CRITICAL **: gtk_widget_destroy: assertion 'GTK_IS_WIDGET (widget)' failed (xfce4-panel:21234): xfce4-panel-CRITICAL **: panel-window.c:3073 (panel_window_thaw_autohide): expression 'window->autohide_block > 0' failed
The panel heavily relies on libwnck for this and the library is not very actively maintained upstream nowadays, so I sort of suspect that the root cause may lie there. I myself have seen this issue a few times over the last year, but not very often and definitely found no way of reproducing it.
This happens basically daily for me. I can recognize all of those symptons and in addition this weirdness: - If I have multiple workspaces with windows on them open and I change Window Buttons > "Show windows from all workspaces", some of the windows on the panel's Window Buttons list get on top of the existing ones (looks like a graphical glitch) - If Window Buttons > Sorting order is set to "None, allow drag-and-drop", the dragging sometimes does not *visually* work - the window position is changed but only after the panel refreshes itself Hard to reproduce. Quite often it seems to be triggered when a new window is spawned from an already existing window (e.g. detaching a tab from a terminal window or Chromium browser). I have a dual monitor setup too. > Under equally mysterious circumstances, the panel usually starts working again after a while. One immediate solution I've found is to change workspace back and forth. Then the panel refreshes and shows everything correctly right away.
A similar issue happened to me last week with CS:GO when I tried to launch it twice, and today it happened with IntelliJ, I don't know why it opened three windows, one of them was "broken", it rendered gibberish. In both cases the zombie windows also appeared on Xfwm4's tabwin (alt+tab), perhaps it may be a Xorg server bug.
*** Bug 14854 has been marked as a duplicate of this bug. ***
Any sign of a fix? I have a Fedora build to do shortly and I can not let this bug loose on the unsuspecting public, especially after talking Linux up the way I do. It is Fedora 28 (nearing end of life) and Xfce 4.12 or Mate. And I really adore Xfce!
@Todd: I wouldn't say that I know how to fix the bug, but I can investigate. Also, as I mentioned earlier, libwnck isn't well-maintained anymore. So in the end the fix may not be under our direct control.
Hi Simon, Thank you. Much appreciated! I think there may be a hint as to what is causing this. "Time" corrects the problem. Also, is there some "refresh" command I an manually run to see if the problem clears up. If "libwnck" is the issue, it must be driving everyone else nuts that uses this gnome utility. If we can isolate it down to libwnck, then it would be a good start to substituting something else that is maintained. I am hoping it is something under your control. This started as of 4.13 and was not an issue under 4.12. -T
You can manually "fix" it by running "xfce4-panel -r". That reloads the whole panel and consequently also refreshes the tasklist.
Possibly related to Bug #15318.
Just now a bunch of programs were missing from Panel 0. `xfce4-panel -r` fixed it.
@Todd: Have you been able to test with the fix in Xfwm4?
Panel 0 was completely missing this morning's boot and it fix that as well. I do not understand what you mean by Xfwm4?
@Todd: Please continue reading here: https://bugzilla.xfce.org/show_bug.cgi?id=15318
Yippee!!!
If panel window stop updating properly, next trick helps me: hover mouse cursor over widget "Show Desktop" (it should be located on the same panel). Xfce 4.12 (Ubuntu 19.04 x64)
I believe this is the same issue as Bug #14394
Created attachment 8767 Example
*** This bug has been marked as a duplicate of bug 14394 ***
As Robert correctly pointed out, this bug had been reported before. To avoid duplicate conversations I decided to close the younger bug report.