Wingpanel Disappeared -- And Won't Come Back!

Question

This seems to be a recurring question on this forum, but I haven't seen an answer (other than rebooting) that solves the problem.

In my case, the wingpanel shows for a second, looks like it is trying hard to push down from the top of the screen, then, after a few attempts dies a sad and lonely death.

Here is what terminal reports when attempting to run wingpanel:

$ wingpanel

(wingpanel:5077): Gtk-WARNING **: Theme parsing error: gtk-widgets.css:2045:14: 'min-height' is not a valid property name

(wingpanel:5077): Gtk-WARNING **: Theme parsing error: gtk-widgets.css:2046:13: 'min-width' is not a valid property name

(wingpanel:5077): Gtk-WARNING **: Theme parsing error: gtk-widgets.css:2051:13: 'min-width' is not a valid property name
[INFO 19:43:29.254521] Application.vala:153: System Panel version: 2.0.2
[INFO 19:43:29.254562] Application.vala:155: Kernel version: 4.4.0-77-generic
[FATAL 19:43:29.309470] display_widget_set_icon_name: assertion 'self != NULL' failed
[FATAL 19:43:29.309798] display_widget_set_icon_name: assertion 'self != NULL' failed
Error: GDBus.Error:org.freedesktop.login1.NoSuchUser: No user 1002 known or logged in
Error: GDBus.Error:org.freedesktop.login1.NoSuchUser: No user 1002 known or logged in
[02:43:29.435759 Gtk-Warning] Theme parsing error: gtk-widgets.css:2045:14: 'min-height' is not a valid property name
[02:43:29.435789 Gtk-Warning] Theme parsing error: gtk-widgets.css:2046:13: 'min-width' is not a valid property name
[02:43:29.435816 Gtk-Warning] Theme parsing error: gtk-widgets.css:2051:13: 'min-width' is not a valid property name
[02:43:29.462108 Critical] string_to_string: assertion 'self != NULL' failed
[02:43:29.507269 GLib-Critical] g_hash_table_get_keys: assertion 'hash_table != NULL' failed
[02:43:29.534970 Gtk-Critical] gtk_window_resize: assertion 'width > 0' failed
[02:43:29.650466 Warning] [DesktopFileInfo] Not Application-type desktop entry
[02:43:29.652287 Warning] [DesktopFileInfo] Key file contains key 'Hidden' which has a value that cannot be interpreted.
[02:43:29.698815 Warning] [DesktopFileInfo] Unable to get exec for Other
[02:43:29.752826 GLib-GObject-Warning] cannot register existing type 'BluetoothServicesObjectManager'
[02:43:29.752840 GLib-Critical] g_once_init_leave: assertion 'result != 0' failed
[02:43:29.752848 GLib-GObject-Critical] g_object_new: assertion 'G_TYPE_IS_OBJECT (object_type)' failed
[02:43:29.752855 GLib-GObject-Critical] g_object_bind_property_full: assertion 'G_IS_OBJECT (source)' failed
[02:43:29.787003 Info] Tweaks.vala:307: Activating Tweak plug
[ERROR 19:43:29.854136] [GLib-GIO] Settings schema 'org.pantheon.terminal.settings' does not contain a key named 'opacity'
Trace/breakpoint trap (core dumped)

Is there a fix to this missing wingpanel issue? Without wingpanel, I can't really use the OS.

Answer 1

It looks as though you've installed Elementary Tweaks from an unsupported PPA. To fix the issue, you'll need to uninstall elementary tweaks using:

sudo apt remove elementary-tweaks

After that, wingpanel should start working again.

You can then then remove the incorrect PPA following the instructions found here.

If you still want elementary tweaks installed, you can install the correct PPA from https://launchpad.net/~philip.scott/+archive/ubuntu/elementary-tweaks