title: Office AddIn button's icon won't show up
body: <p>Here's extract from the manifest's Host</p>
  
  <pre><code>&lt;ExtensionPoint xsi:type="PrimaryCommandSurface"&gt;
      &lt;CustomTab id="MyTab"&gt;
          &lt;Group id="Raporty.GroupPabcd"&gt;
              &lt;Label resid="Raporty.GroupPabcd.Label" /&gt;
              &lt;Icon&gt;
                  &lt;bt:Image resid="Raporty.Icon1_16" size="16" /&gt;
                  &lt;bt:Image resid="Raporty.Icon1_20" size="20" /&gt;
                  &lt;bt:Image resid="Raporty.Icon1_24" size="24" /&gt;
                  &lt;bt:Image resid="Raporty.Icon1_32" size="32" /&gt;
                  &lt;bt:Image resid="Raporty.Icon1_40" size="40" /&gt;
                  &lt;bt:Image resid="Raporty.Icon1_48" size="48" /&gt;
                  &lt;bt:Image resid="Raporty.Icon1_64" size="64" /&gt;
                  &lt;bt:Image resid="Raporty.Icon1_80" size="80" /&gt;
              &lt;/Icon&gt;
  
              &lt;Control xsi:type="Button" id="RaportPabcd.Button"&gt;
                  &lt;Label resid="RaportPabcd.Button.Label" /&gt;
                  &lt;Supertip&gt;
                      &lt;Title resid="RaportPabcd.Button.Label" /&gt;
                      &lt;Description resid="RaportPabcd.Button.Tooltip" /&gt;
                  &lt;/Supertip&gt;
                  &lt;Icon&gt;
                      &lt;bt:Image resid="Raporty.Icon1_16" size="16" /&gt;
                      &lt;bt:Image resid="Raporty.Icon1_20" size="20" /&gt;
                      &lt;bt:Image resid="Raporty.Icon1_24" size="24" /&gt;
                      &lt;bt:Image resid="Raporty.Icon1_32" size="32" /&gt;
                      &lt;bt:Image resid="Raporty.Icon1_40" size="40" /&gt;
                      &lt;bt:Image resid="Raporty.Icon1_48" size="48" /&gt;
                      &lt;bt:Image resid="Raporty.Icon1_64" size="64" /&gt;
                      &lt;bt:Image resid="Raporty.Icon1_80" size="80" /&gt;
                  &lt;/Icon&gt;
  
                  &lt;Action xsi:type="ShowTaskpane"&gt;
                      &lt;TaskpaneId&gt;ButtonId1&lt;/TaskpaneId&gt;
                      &lt;SourceLocation resid="Contoso.Taskpane.Url" /&gt;
                  &lt;/Action&gt;
              &lt;/Control&gt;
  
          &lt;/Group&gt;
          &lt;Label resid="Raporty.Tab.Label" /&gt;
      &lt;/CustomTab&gt;
  &lt;/ExtensionPoint&gt;
  </code></pre>
  
  <p>as well as the resources </p>
  
  <pre><code>&lt;Resources&gt;
      &lt;bt:Images&gt;
          &lt;bt:Image id="Raporty.Icon1_16" DefaultValue="~remoteAppUrl/Images/ReportIcons/report_1_16.png" /&gt;
          &lt;bt:Image id="Raporty.Icon1_20" DefaultValue="~remoteAppUrl/Images/ReportIcons/report_1_20.png" /&gt;
          &lt;bt:Image id="Raporty.Icon1_24" DefaultValue="~remoteAppUrl/Images/ReportIcons/report_1_24.png" /&gt;
          &lt;bt:Image id="Raporty.Icon1_32" DefaultValue="~remoteAppUrl/Images/ReportIcons/report_1_32.png" /&gt;
          &lt;bt:Image id="Raporty.Icon1_40" DefaultValue="~remoteAppUrl/Images/ReportIcons/report_1_40.png" /&gt;
          &lt;bt:Image id="Raporty.Icon1_48" DefaultValue="~remoteAppUrl/Images/ReportIcons/report_1_48.png" /&gt;
          &lt;bt:Image id="Raporty.Icon1_64" DefaultValue="~remoteAppUrl/Images/ReportIcons/report_1_64.png" /&gt;
          &lt;bt:Image id="Raporty.Icon1_80" DefaultValue="~remoteAppUrl/Images/ReportIcons/report_1_80.png" /&gt;
      &lt;/bt:Images&gt;
  &lt;/Resources&gt;
  </code></pre>
  
  <p>Problem is that the button shows the default icon </p>
  
  <p><a href="https://i.stack.imgur.com/mMx2X.png" rel="nofollow"><img src="https://i.stack.imgur.com/mMx2X.png" alt="enter image description here"></a></p>
  
  <p>I tried to access the image directly in the browser (i.e. <a href="http://localhost/ExcelWebWeb/Images/ReportIcons/report_1_32.png" rel="nofollow">http://localhost/ExcelWebWeb/Images/ReportIcons/report_1_32.png</a>) and it does show up </p>
  
  <p>I have taken a look at the IIS logs to see if the image was even queried by the Excel app, but it wasn't. I can only see access logs from my local browser to the icons while the addin only queries the html/js files (for the TaskPane) without querying for the button's image. </p>