I have built a Word addin manifest that inserts a button in the Home tab. Button opens a taskpane, addin does not use commands, therefore is suitable not only for Office 2016, but for Office 2013 as well.
Even though the addin works fine on both Office versions, the button is inserted into the Home tab on Office 2016, but not on 2013.
I suspect there may be something else expected in the manifest, even though I read that VersionOverrides node is sufficient to support both versions.
This is the manifest that shows no problem in Word 2016:
<?xml version="1.0" encoding="UTF-8" standalone="yes"?>
<OfficeApp
xmlns="http://schemas.microsoft.com/office/appforoffice/1.1"
xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xmlns:bt="http://schemas.microsoft.com/office/officeappbasictypes/1.0"
xmlns:ov="http://schemas.microsoft.com/office/taskpaneappversionoverrides"
xsi:type="TaskPaneApp">
<Id>05c2e1c9-3e1d-406e-9a91-e9ac64854143</Id>
<Version>1.0.0.0</Version>
<ProviderName>DEMO</ProviderName>
<DefaultLocale>en-US</DefaultLocale>
<DisplayName DefaultValue="Name">
<Override Locale="en-US" Value="Name" />
</DisplayName>
<Description DefaultValue="Addin" >
<Override Locale="en-US" Value="Addin" />
</Description>
<IconUrl DefaultValue="https://localhost:3000/assets/logo-32.png"/>
<HighResolutionIconUrl DefaultValue="https://localhost:3000/assets/logo-80.png"/>
<SupportUrl DefaultValue="support.com" />
<AppDomains>
<AppDomain>localhost</AppDomain>
</AppDomains>
<Hosts>
<Host Name="Document"/>
</Hosts>
<DefaultSettings>
<SourceLocation DefaultValue="https://localhost:3000/taskpane.html"/>
</DefaultSettings>
<Permissions>ReadWriteDocument</Permissions>
<ov:VersionOverrides xmlns="http://schemas.microsoft.com/office/taskpaneappversionoverrides" xsi:type="VersionOverridesV1_0">
<ov:Hosts>
<ov:Host xsi:type="Document">
<ov:DesktopFormFactor>
<ov:GetStarted>
<ov:Title resid="GetStarted.Title"/>
<ov:Description resid="GetStarted.Description"/>
<ov:LearnMoreUrl resid="GetStarted.LearnMoreUrl"/>
</ov:GetStarted>
<ov:ExtensionPoint xsi:type="PrimaryCommandSurface">
<ov:OfficeTab id="TabHome">
<ov:Group id="AddinGroup">
<ov:Label resid="CommandsGroup.Label" />
<ov:Icon>
<bt:Image size="16" resid="Icon.16x16" />
<bt:Image size="32" resid="Icon.32x32" />
<bt:Image size="80" resid="Icon.80x80" />
</ov:Icon>
<ov:Control xsi:type="Button" id="AddinButton">
<ov:Label resid="AddinButton.Label" />
<ov:Supertip>
<ov:Title resid="AddinButton.Label" />
<ov:Description resid="AddinButton.Tooltip" />
</ov:Supertip>
<ov:Icon>
<bt:Image size="16" resid="Icon.16x16" />
<bt:Image size="32" resid="Icon.32x32" />
<bt:Image size="80" resid="Icon.80x80" />
</ov:Icon>
<ov:Action xsi:type="ShowTaskpane">
<ov:TaskpaneId>AddinButtonTaskpane</ov:TaskpaneId>
<ov:SourceLocation resid="AddinTaskpane.Url" />
</ov:Action>
</ov:Control>
</ov:Group>
</ov:OfficeTab>
</ov:ExtensionPoint>
</ov:DesktopFormFactor>
</ov:Host>
</ov:Hosts>
<ov:Resources>
<bt:Images>
<bt:Image id="Icon.16x16" DefaultValue="https://localhost:3000/assets/logo-16.png"/>
<bt:Image id="Icon.32x32" DefaultValue="https://localhost:3000/assets/logo-32.png"/>
<bt:Image id="Icon.80x80" DefaultValue="https://localhost:3000/assets/logo-80.png"/>
</bt:Images>
<bt:Urls>
<bt:Url id="GetStarted.LearnMoreUrl" DefaultValue="http://started.com" />
<bt:Url id="AddinTaskpane.Url" DefaultValue="https://localhost:3000/taskpane.html" />
</bt:Urls>
<bt:ShortStrings>
<bt:String id="GetStarted.Title" DefaultValue="GetStarted" >
</bt:String>
<bt:String id="CommandsGroup.Label" DefaultValue="Addin" >
</bt:String>
<bt:String id="AddinButton.Label" DefaultValue="Addin" >
</bt:String>
</bt:ShortStrings>
<bt:LongStrings>
<bt:String id="GetStarted.Description" DefaultValue="GetStarted" >
</bt:String>
<bt:String id="AddinButton.Tooltip" DefaultValue="Addin" >
</bt:String>
</bt:LongStrings>
</ov:Resources>
</ov:VersionOverrides>
</OfficeApp>
