Can't specify requirements set for OfficeApp manifest.xml

I have an Office add-in/TaskPane app.

When I try to specify the requirements set for this app in my manifest.xml, I am getting the following error from office-addin-validator:

The element OfficeApp in namespace http://schemas.microsoft.com/office/appforoffice/1.1 has invalid child element Requirements in namespace http://schemas.microsoft.com/office/appforoffice/1.1

The documentation makes it very clear that Requirements is in fact allowed in this location.

I am able to add the requirement set inside the VersionOverrides tag, and that section looks like:

<VersionOverrides xmlns="http://schemas.microsoft.com/office/taskpaneappversionoverrides" xsi:type="VersionOverridesV1_0">
    <Requirements>
        <bt:Sets>
            <bt:Set Name="ExcelApi" MinVersion="1.1"/>
        </bt:Sets>
    </Requirements>
    <!--- ... -->
</VersionOverrides>

However, office-addin-validator does not correctly identify that older versions of Excel are not supported.

What is the correct way to do this? I can't tell if this is a bug in the office-addin-validator tool or outdated documentation.

EDIT

Here is a failing manifest:

<?xml version="1.0" encoding="UTF-8"?>
<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>999dfa02-364b-450c-a66b-b4baaae2e6f9</Id>
    <Version>1.0.0.0</Version>
    <ProviderName>[Provider name]</ProviderName>
    <DefaultLocale>en-US</DefaultLocale>
    <DisplayName DefaultValue="My Office Add-in" />
    <Description DefaultValue="[Workbook Add-in description]"/>
    <IconUrl DefaultValue="https://localhost:3000/assets/icon-32.png" />
    <HighResolutionIconUrl DefaultValue="https://localhost:3000/assets/hi-res-icon.png"/>
    <SupportUrl DefaultValue="[Insert the URL of a page that provides support information for the app]"/>
    <AppDomains>
        <AppDomain>AppDomain1</AppDomain>
        <AppDomain>AppDomain2</AppDomain>
        <AppDomain>AppDomain3</AppDomain>
    </AppDomains>
    <Hosts>
        <Host Name="Workbook" />
    </Hosts>
    <DefaultSettings>
        <SourceLocation DefaultValue="https://localhost:3000/index.html" />
    </DefaultSettings>
    <Permissions>ReadWriteDocument</Permissions>
    <VersionOverrides xmlns="http://schemas.microsoft.com/office/taskpaneappversionoverrides" xsi:type="VersionOverridesV1_0">
        <Hosts>
            <Host xsi:type="Workbook">
                <DesktopFormFactor>
                    <GetStarted>
                        <Title resid="Contoso.GetStarted.Title"/>
                        <Description resid="Contoso.GetStarted.Description"/>
                        <LearnMoreUrl resid="Contoso.GetStarted.LearnMoreUrl"/>
                    </GetStarted>
                    <FunctionFile resid="Contoso.DesktopFunctionFile.Url" />
                    <ExtensionPoint xsi:type="PrimaryCommandSurface">
                        <OfficeTab id="TabHome">
                            <Group id="Contoso.Group1">
                                <Label resid="Contoso.Group1Label" />
                                <Icon>
                                    <bt:Image size="16" resid="Contoso.tpicon_16x16" />
                                    <bt:Image size="32" resid="Contoso.tpicon_32x32" />
                                    <bt:Image size="80" resid="Contoso.tpicon_80x80" />
                                </Icon>
                                <Control xsi:type="Button" id="Contoso.TaskpaneButton">
                                    <Label resid="Contoso.TaskpaneButton.Label" />
                                    <Supertip>
                                        <Title resid="Contoso.TaskpaneButton.Label" />
                                        <Description resid="Contoso.TaskpaneButton.Tooltip" />
                                    </Supertip>
                                    <Icon>
                                        <bt:Image size="16" resid="Contoso.tpicon_16x16" />
                                        <bt:Image size="32" resid="Contoso.tpicon_32x32" />
                                        <bt:Image size="80" resid="Contoso.tpicon_80x80" />
                                    </Icon>
                                    <Action xsi:type="ShowTaskpane">
                                        <TaskpaneId>ButtonId1</TaskpaneId>
                                        <SourceLocation resid="Contoso.Taskpane.Url" />
                                    </Action>
                                </Control>
                            </Group>
                        </OfficeTab>
                    </ExtensionPoint>
                </DesktopFormFactor>
            </Host>
        </Hosts>
        <Resources>
            <bt:Images>
                <bt:Image id="Contoso.tpicon_16x16" DefaultValue="https://localhost:3000/assets/icon-16.png" />
                <bt:Image id="Contoso.tpicon_32x32" DefaultValue="https://localhost:3000/assets/icon-32.png" />
                <bt:Image id="Contoso.tpicon_80x80" DefaultValue="https://localhost:3000/assets/icon-80.png" />
            </bt:Images>
            <bt:Urls>
                <bt:Url id="Contoso.Taskpane.Url" DefaultValue="https://localhost:3000/index.html" />
                <bt:Url id="Contoso.GetStarted.LearnMoreUrl" DefaultValue="https://go.microsoft.com/fwlink/?LinkId=276812" />
                <bt:Url id="Contoso.DesktopFunctionFile.Url" DefaultValue="https://localhost:3000/function-file/function-file.html" />
            </bt:Urls>
            <bt:ShortStrings>
                <bt:String id="Contoso.TaskpaneButton.Label" DefaultValue="Show Taskpane" />
                <bt:String id="Contoso.Group1Label" DefaultValue="Commands Group" />
                <bt:String id="Contoso.GetStarted.Title" DefaultValue="Get started with your sample add-in!" />
            </bt:ShortStrings>
            <bt:LongStrings>
                <bt:String id="Contoso.TaskpaneButton.Tooltip" DefaultValue="Click to Show a Taskpane" />
                <bt:String id="Contoso.GetStarted.Description" DefaultValue="Your sample add-in loaded succesfully. Go to the HOME tab and click the 'Show Taskpane' button to get started." />
            </bt:LongStrings>
        </Resources>
    </VersionOverrides>
    <Requirements>
        <Sets DefaultMinVersion="1.1">
            <Set Name="WordApi" MinVersion="1.3"/>
            <Set Name="DialogApi"/>
            <Set Name="ImageCoercion"/>
        </Sets>
    </Requirements>
</OfficeApp>

Solution

The sequence of the elements is included in the scheme. It is failing because you are adding Requirements in the wrong sequence. You need to put the Requirements section immediately before the DefaultSettings section:

<Hosts>
    <Host Name="Workbook" />
</Hosts>
<Requirements>
    <Sets DefaultMinVersion="1.1">
        <Set Name="WordApi" MinVersion="1.3"/>
        <Set Name="DialogApi"/>
        <Set Name="ImageCoercion"/>
    </Sets>
</Requirements>    
<DefaultSettings>
    <SourceLocation DefaultValue="https://localhost:3000/index.html" />
</DefaultSettings>