Outlook AddIn图标突然消失问题求助（含Manifest配置文件）

我们的Outlook Add-in应用图标突然从Outlook界面消失，多个拥有独立Microsoft 365租户的客户都反馈了这个问题。我们尝试重新读取Manifest文件来安装应用，但问题仍未解决，而且在网络上也找不到相关症状的解决方案。

以下是该Add-in的Manifest配置文件：

<?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:mailappor="http://schemas.microsoft.com/office/mailappversionoverrides/1.0"
          xsi:type="MailApp">

  <!-- Begin Basic Settings: Add-in metadata, used for all versions of Office unless override provided. -->

  <!-- IMPORTANT! Id must be unique for your add-in, if you reuse this manifest ensure that you change this id to a new GUID. -->
  <Id>b5db42d1-a33c-4b2a-9eb8-96f406feeea9</Id>

  <!--Version. Updates from the store only get triggered if there is a version change. -->
  <Version>2023.03.2.0</Version>
  <ProviderName>Softmakers BV</ProviderName>
  <DefaultLocale>nl-NL</DefaultLocale>
  <!-- The display name of your add-in. Used on the store and various places of the Office UI such as the add-ins dialog. -->
  <DisplayName DefaultValue="Tim" />
  <Description DefaultValue="Bewaar jouw emails in Tim"/>

  <!-- Icon for your add-in. Used on installation screens and the add-ins dialog. -->
  <IconUrl DefaultValue="https://<blurred>.timsaas.com/Tim365/assets/icon-32.png" />
  <HighResolutionIconUrl DefaultValue="https://<blurred>.timsaas.com/Tim365/assets/logo-filled.png"/>

  <!--If you plan to submit this add-in to the Office Store, uncomment the SupportUrl element below-->
  <SupportUrl DefaultValue="http://www.softmakers.nl" />

  <!-- Domains that will be allowed when navigating. For example, if you use ShowTaskpane and then have an href link, navigation will only be allowed if the domain is on this list. -->
  <AppDomains>
    <AppDomain>https://login.windows.net</AppDomain>
    <AppDomain>https://login.microsoftonline.com</AppDomain>  
    <AppDomain>https://timsaas.eu.auth0.com</AppDomain>
    <AppDomain>https://timsaas.com</AppDomain>
    <AppDomain>https://<blurred>.timsaas.com</AppDomain>
  </AppDomains>
  <!--End Basic Settings. -->

  <Hosts>
    <Host Name="Mailbox" />
  </Hosts>
  <Requirements>
    <Sets>
      <Set Name="Mailbox" MinVersion="1.1" />
    </Sets>
  </Requirements>
  <FormSettings>
    <Form xsi:type="ItemRead">
      <DesktopSettings>
        <SourceLocation DefaultValue="https://<blurred>.timsaas.com/Tim365/outlook-save"/>
        <RequestedHeight>250</RequestedHeight>
      </DesktopSettings>
    </Form>
    <Form xsi:type="ItemEdit">
      <DesktopSettings>
        <SourceLocation DefaultValue="https://<blurred>.timsaas.com/Tim365/outlook-send"/>
      </DesktopSettings>
    </Form>
  </FormSettings>

  <Permissions>ReadWriteItem</Permissions>
  <Rule xsi:type="RuleCollection" Mode="Or">
    <Rule xsi:type="ItemIs" ItemType="Message" FormType="Edit" />
    <Rule xsi:type="ItemIs" ItemType="Message" FormType="Read" />
  </Rule>
  <DisableEntityHighlighting>false</DisableEntityHighlighting>

  <VersionOverrides xmlns="http://schemas.microsoft.com/office/mailappversionoverrides" xsi:type="VersionOverridesV1_0">
    <Requirements>
      <bt:Sets DefaultMinVersion="1.3">
        <bt:Set Name="Mailbox" />
      </bt:Sets>
    </Requirements>
    <Hosts>
      <Host xsi:type="MailHost">

        <DesktopFormFactor>
          <!-- Location of the Functions that UI-less buttons can trigger (ExecuteFunction Actions). -->
          <FunctionFile resid="functionFile" />

          <!-- Message Read -->
          <ExtensionPoint xsi:type="MessageReadCommandSurface">
            <!-- Use the default tab of the ExtensionPoint or create your own with <CustomTab id="myTab"> -->
            <OfficeTab id="TabDefault">
              <!-- Up to 6 Groups added per Tab -->
              <Group id="msgReadGroup">
                <Label resid="groupLabel" />
                <!-- Launch the add-in : task pane button -->
                <Control xsi:type="Button" id="msgReadOpenPaneButton">
                  <Label resid="paneReadButtonLabel" />
                  <Supertip>
                    <Title resid="paneReadSuperTipTitle" />
                    <Description resid="paneReadSuperTipDescription" />
                  </Supertip>
                  <Icon>
                    <bt:Image size="16" resid="icon16" />
                    <bt:Image size="32" resid="icon32" />
                    <bt:Image size="80" resid="icon80" />
                  </Icon>
                  <Action xsi:type="ShowTaskpane">
                    <SourceLocation resid="messageReadTaskPaneUrl" />
                  </Action>
                </Control>
                <!-- Go to http://aka.ms/ButtonCommands to learn how to add more Controls: ExecuteFunction and Menu -->
              </Group>
            </OfficeTab>
          </ExtensionPoint>

          <!-- Message Compose -->
          <ExtensionPoint xsi:type="MessageComposeCommandSurface">
            <!-- Use the default tab of the ExtensionPoint or create your own with <CustomTab id="myTab"> -->
            <OfficeTab id="TabDefault">
              <!-- Up to 6 Groups added per Tab -->
              <Group id="msgComposeGroup">
                <Label resid="groupLabel" />
                <!-- Launch the add-in : task pane button -->
                <Control xsi:type="Button" id="msgComposeOpenPaneButton">
                  <Label resid="paneComposeButtonLabel" />
                  <Supertip>
                    <Title resid="paneComposeSuperTipTitle" />
                    <Description resid="paneComposeSuperTipDescription" />
                  </Supertip>
                  <Icon>
                    <bt:Image size="16" resid="icon16" />
                    <bt:Image size="32" resid="icon32" />
                    <bt:Image size="80" resid="icon80" />
                  </Icon>
                  <Action xsi:type="ShowTaskpane">
                    <SourceLocation resid="messageComposeTaskPaneUrl" />
                  </Action>
                </Control>
                <!-- Go to http://aka.ms/ButtonCommands to learn how to add more Controls: ExecuteFunction and Menu -->
              </Group>
            </OfficeTab>
          </ExtensionPoint>

          <!-- Appointment Compose Organizer -->
          <ExtensionPoint xsi:type="AppointmentOrganizerCommandSurface">
            <!-- Use the default tab of the ExtensionPoint or create your own with <CustomTab id="myTab"> -->
            <OfficeTab id="TabDefault">
              <!-- Up to 6 Groups added per Tab -->
              <Group id="appComposeGroup">
                <Label resid="groupLabel" />
                <!-- Launch the add-in : task pane button -->
                <Control xsi:type="Button" id="appComposeOpenPaneButton">
                  <Label resid="paneComposeButtonLabel" />
                  <Supertip>
                    <Title resid="paneComposeSuperTipTitle" />
                    <Description resid="paneComposeSuperTipDescription" />
                  </Supertip>
                  <Icon>
                    <bt:Image size="16" resid="icon16" />
                    <bt:Image size="32" resid="icon32" />
                    <bt:Image size="80" resid="icon80" />
                  </Icon>
                  <Action xsi:type="ShowTaskpane">
                    <SourceLocation resid="appointmentComposeTaskPaneUrl" />
                  </Action>
                </Control>
                <!-- Go to http://aka.ms/ButtonCommands to learn how to add more Controls: ExecuteFunction and Menu -->
              </Group>
            </OfficeTab>
          </ExtensionPoint>

          <!-- Appointment Compose Attendee -->
          <ExtensionPoint xsi:type="AppointmentAttendeeCommandSurface">
            <!-- Use the default tab of the ExtensionPoint or create your own with <CustomTab id="myTab"> -->
            <OfficeTab id="TabDefault">
              <!-- Up to 6 Groups added per Tab -->
              <Group id="appAttendeeGroup">
                <Label resid="groupLabel" />
                <!-- Launch the add-in : task pane button -->
                <Control xsi:type="Button" id="appAttendeeButton">
                  <Label resid="paneComposeButtonLabel" />
                  <Supertip>
                    <Title resid="paneComposeSuperTipTitle" />
                    <Description resid="paneComposeSuperTipDescription" />
                  </Supertip>
                  <Icon>
                    <bt:Image size="16" resid="icon16" />
                    <bt:Image size="32" resid="icon32" />
                    <bt:Image size="80" resid="icon80" />
                  </Icon>
                  <Action xsi:type="ShowTaskpane">
                    <SourceLocation resid="appointmentComposeTaskPaneUrl" />
                  </Action>
                </Control>
                <!-- Go to http://aka.ms/ButtonCommands to learn how to add more Controls: ExecuteFunction and Menu -->
              </Group>
            </OfficeTab>
          </ExtensionPoint>

          <!-- Go to http://aka.ms/ExtensionPointsCommands to learn how to add more Extension Points: MessageRead, AppointmentOrganizer, AppointmentAttendee -->
        </DesktopFormFactor>
      </Host>
    </Hosts>

    <Resources>
      <bt:Images>
        <bt:Image id="icon16" DefaultValue="https://<blurred>.timsaas.com/Tim365/assets/icon-16.png"/>
        <bt:Image id="icon32" DefaultValue="https://<blurred>.timsaas.com/Tim365/assets/icon-32.png"/>
        <bt:Image id="icon80" DefaultValue="https://<blurred>.timsaas.com/Tim365/assets/icon-80.png"/>
      </bt:Images>
      <bt:Urls>
        <!-- <bt:Url id="functionFile" DefaultValue="https://localhost:3000/function-file/function-file.html"/> -->
        <bt:Url id="messageReadTaskPaneUrl" DefaultValue="https://<blurred>.timsaas.com/Tim365/outlook-save"/>
        <bt:Url id="messageComposeTaskPaneUrl" DefaultValue="https://<blurred>.timsaas.com/Tim365/outlook-send"/>
        <bt:Url id="appointmentComposeTaskPaneUrl" DefaultValue="https://<blurred>.timsaas.com/Tim365/outlook-calr"/>
      </bt:Urls>
      <bt:ShortStrings>
        <bt:String id="groupLabel" DefaultValue="My Add-in Group"/>
        <bt:String id="customTabLabel"  DefaultValue="My Add-in Tab"/>
        <bt:String id="paneReadButtonLabel" DefaultValue="Tim Info"/>
        <bt:String id="paneReadSuperTipTitle" DefaultValue="Tim email bewaren"/>
        <bt:String id="paneComposeButtonLabel" DefaultValue="Tim Info"/>
        <bt:String id="paneComposeSuperTipTitle" DefaultValue="Tim email opstellen"/>
      </bt:ShortStrings>
      <bt:LongStrings>
        <bt:String id="paneReadSuperTipDescription" DefaultValue="Opens a pane displaying all available properties. This is an example of a button that opens a task pane."/>
        <bt:String id="paneComposeSuperTipDescription" DefaultValue="Opens a pane displaying all available properties. This is an example of a button that opens a task pane."/>
      </bt:LongStrings>
    </Resources>
  </VersionOverrides>
</OfficeApp>

注：配置文件中的<blurred>用于隐藏服务器名称，图标原样式可通过内部共享文件查看。

恳请各位提供帮助！

内容的提问来源于stack exchange，提问作者wilcotroost