XFCE4 panel recovery

Every now and then the xfce4 panel will disappear. There are a number of bugs about this, but few solutions. I've gathered them here.

1. Check if xfce4-panel is running. If not, start it using your user, just 'xfce4-panel' in a terminal window. That might do it.
2. Remove ~/.config, log out, then log back in. That might do it. It might be overkill. Instead you might try deleting ~/.config/xfce4/panel, then log out and back in.
3. Check ~/.config/xfce4/panel for a file named panel.xml. If you have one, delete it. Create a new one using this content:
   
   <?xml version="1.0" encoding="UTF-8"?>
   <!DOCTYPE config SYSTEM "config.dtd">
   <panels>
     <panel>
        <properties>
          <property name="size" value="27"/>
          <property name="monitor" value="0"/>
          <property name="screen-position" value="10"/>
          <property name="fullwidth" value="1"/>
          <property name="xoffset" value="0"/>
          <property name="yoffset" value="996"/>
          <property name="handlestyle" value="0"/>
          <property name="autohide" value="0"/>
          <property name="transparency" value="25"/>
          <property name="activetrans" value="0"/>
        </properties>
        <items>
           <item name="xfce4-menu" id="5"/>
           <item name="separator" id="6"/>
           <item name="launcher" id="10"/>
           <item name="launcher" id="11934103341"/>
           <item name="launcher" id="11934284041"/>
           <item name="actions" id="12"/>
           <item name="separator" id="11934162861"/>
           <item name="tasklist" id="11934220980"/>
           <item name="datetime" id="11934096510"/>
        </items>
     </panel>
   </panels> 
   
   
   Then log out and back in and the panels might reappear.