Comment 7 for bug 1608924

After running wingpanel on debug mode I got the following output:
Could it be the "Sample Indicator"?

[INFO 18:29:08.933191] Application.vala:155: Painel de sistema version: 2.0
[INFO 18:29:08.933233] Application.vala:157: Kernel version: 4.4.0-31-generic
[DEBUG 18:29:08.934067] [Gtk] Connecting to session manager
[DEBUG 18:29:08.935783] Indicator.vala:73: Activating Bluetooth Indicator
[DEBUG 18:29:08.936297] Indicator.vala:42: Bluetooth Indicator started
[DEBUG 18:29:08.936362] IndicatorManager.vala:314: bluetooth registered
[DEBUG 18:29:08.939882] Indicator.vala:94: Activating Power Indicator
[DEBUG 18:29:08.939953] IndicatorManager.vala:314: network registered
[DEBUG 18:29:08.940539] Indicator.vala:100: Activating Power Indicator
[DEBUG 18:29:08.940602] IndicatorManager.vala:314: power registered
[DEBUG 18:29:08.941025] Indicator.vala:160: Activating Sample Indicator
[DEBUG 18:29:08.941086] IndicatorManager.vala:314: session registered
[DEBUG 18:29:08.942763] Indicator.vala:396: Activating Sound Indicator
[DEBUG 18:29:08.947710] Settings.vala:163: Loading settings from schema 'org.pantheon.desktop.wingpanel.indicators.sound'
[DEBUG 18:29:08.947962] IndicatorManager.vala:314: sound registered
[DEBUG 18:29:08.948885] Indicator.vala:207: Activating Notifications Indicator
[DEBUG 18:29:08.949031] IndicatorManager.vala:314: messages registered
[DEBUG 18:29:08.960560] Indicator.vala:150: Activating DateTime Indicator
[DEBUG 18:29:08.960683] IndicatorManager.vala:314: datetime registered
[DEBUG 18:29:08.962378] Slingshot.vala:80: Activating Slingshot
[DEBUG 18:29:08.962521] IndicatorManager.vala:314: app-launcher registered
[DEBUG 18:29:08.963086] Indicator.vala:110: Activating AyatanaCompatibility Meta Indicator
[DEBUG 18:29:08.963328] IndicatorFactory.vala:61: Loading Indicator Library: libapplication.so
[DEBUG 18:29:08.964014] IndicatorManager.vala:314: ayatana_compatibility registered
[DEBUG 18:29:08.983855] User.vala:60: Connection to user account established. User path: /org/freedesktop/login1/user/_1000
[DEBUG 18:29:09.021125] Settings.vala:163: Loading settings from schema 'org.pantheon.desktop.slingshot'
[DEBUG 18:29:09.021444] Settings.vala:163: Loading settings from schema 'org.pantheon.desktop.gala.behavior'
[DEBUG 18:29:09.022379] [Indicator-Application] Connected to Application Indicator Service.
[FATAL 18:29:09.024541] wingpanel_widgets_overlay_icon_set_main_icon_name: assertion 'self != NULL' failed
[DEBUG 18:29:09.024585] Volume-control.vala:657: Setting volume to 0,713028 for profile -1 because 0
[FATAL 18:29:09.024818] wingpanel_widgets_overlay_icon_set_main_icon_name: assertion 'self != NULL' failed
[DEBUG 18:29:09.025024] [Indicator-Application] Request current apps
[DEBUG 18:29:09.025991] sql-schema.vala:204: schema_version is 10
[DEBUG 18:29:09.026514] AppSystem.vala:50: Updating Applications menu tree...
[DEBUG 18:29:09.045306] [Indicator-Application] Building new application entry: :1.45 with icon: dropboxstatus-idle at position 0
[DEBUG 18:29:09.046639] [Indicator-Application] Appending search path: /home/shaxine/.dropbox-dist/dropbox-lnx.x86_64-7.4.30/images
[DEBUG 18:29:09.073331] IndicatorManager.vala:314: ayatana-dropbox-client-14129 registered
[DEBUG 18:29:09.075835] sql-schema.vala:204: schema_version is 10
[17:29:09.127739 GLib-GIO-Critical] g_file_get_child: assertion 'G_IS_FILE (file)' failed
[17:29:09.127762 GLib-GIO-Critical] g_file_query_exists: assertion 'G_IS_FILE(file)' failed
[17:29:09.127767 GLib-GIO-Critical] g_file_get_child: assertion 'G_IS_FILE (file)' failed
[17:29:09.127770 GLib-GIO-Critical] g_file_query_exists: assertion 'G_IS_FILE(file)' failed
[17:29:09.127776 Critical] gee_abstract_collection_get_size: assertion 'self != NULL' failed
[17:29:09.127781 Warning] Theme.vala:508: Currently selected gtk+ theme 'Vertex-Dark' does not provide a dock theme, fallback to the built-in defaults!
[17:29:09.192446 Gtk-Warning] Attempting to add a widget with type AyatanaCompatibilityIndicatorButton to a container of type GtkRevealer, but the widget is already inside a container of type GtkRevealer, please remove the widget from its existing container first.
[17:29:09.192478 Gtk-Warning] Attempting to add a widget with type GtkStack to a container of type WingpanelWidgetsIndicatorPopover, but the widget is already inside a container of type WingpanelWidgetsIndicatorPopover, please remove the widget from its existing container first.
[17:29:09.214848 GLib-Critical] g_hash_table_get_keys: assertion 'hash_table != NULL' failed
[INFO 18:29:09.255081] DBusService.vala:64: Service registration suceeded
[17:29:09.356202 Warning] [DesktopFileInfo] Unable to create AppInfo
[17:29:09.357603 Warning] [DesktopFileInfo] Ficheiro de chave não possui a chave "Type" no grupo "Desktop Entry"
[17:29:09.368976 Warning] [DesktopFileInfo] Unable to get exec for Outras
[17:29:09.370925 Warning] [DesktopFileInfo] Unable to create AppInfo

** (process:23686): CRITICAL **: string_contains: assertion 'self != NULL' failed

** (process:23686): CRITICAL **: string_contains: assertion 'self != NULL' failed
[17:29:09.498249 Info] Tweaks.vala:68: Activating tweaks plug