Signature preview not working in Outlook

Problem:

You experience problems with CodeTwo Email Signatures for Office 365 Add-in in Outlook and Outlook on the web (OWA). For example, the add-in button does not appear in the new email window, is inactive (Fig. 1.) or, in general, the add-in does not work as expected. 

670-1
Fig. 1. Inactive add-in button in the Outlook’s new email window.

Important

Since signatures are added on the server, they are added even if the preview add-in is not deployed or does not work.

Solution:

Issues with CodeTwo Email Signatures for Office 365 Add-in can be caused by several factors. Follow the links below to find a solution that works best in your environment:

Multiple add-ins installed on the same client are incompatible with each other

There are several types of Outlook add-ins, and some of them might interfere with each other. Older types of add-ins, such as COM add-ins, can be incompatible with newer types of add-ins, such as web add-ins. CodeTwo Email Signatures for Office 365 Add-in is an example of a modern web add-in and – unlike COM add-ins – it does not install any code on your machine.

In rare cases, you may need to disable a COM add-in, especially if it uses custom forms, for CodeTwo Email Signatures for Office 365 Add-in to work properly.

To find out which COM add-in causes the issue, you first need to disable all the COM add-ins that you installed (you don’t need to disable the add-ins that are installed by default by Microsoft, such as Microsoft Exchange Add-in) and then enable them again one by one. Remember to restart Outlook after re-enabling each add-in and check if CodeTwo Email Signatures for Office 365 Add-in is active.

To disable and re-enable a COM add-in:

  1. In Outlook, go to File > Options > Add-ins
  2. In the Manage section at the bottom of the window, choose COM Add-ins and click Go (Fig. 2.).

670-2
Fig. 2. Selecting COM Add-ins.

  1. In the window that opens, clear (deselect) the checkboxes for the add-ins that you want to disable and click OK. (Fig. 3.).

670-3
Fig. 3. A list of Outlook COM add-ins. To disable an add-in, clear its checkbox.

  1. Re-enable the disabled add-ins one by one by selecting (checking) them again and restarting Outlook each time to see if the signature preview is working.

After finding out which add-in is the source of the problem, disable it whenever you want to preview your signatures.

You provided a wrong URL during the add-in's installation

During installation, you need to provide the address of the add-in:

  • https://emailsignatures365-addin.codetwo.com/InstallApp - if you use the global version of the software
  • https://emailsignatures365-addin.codetwo.de/InstallApp - if you use the Office 365 Germany version of the software.

If you use the global version of CodeTwo Email Signatures for Office 365, but provide the URL for the Office 365 Germany version (or vice versa), the add-in will not work. To fix the problem, you need to reinstall the add-in by using the correct address.

Learn more about centralized deployment of the signature preview add-in
Learn more about individual installation of the add-in

You are not able to launch the add-in (This add-in could not be started)

When you start the add-in, instead of the signature preview you see the following error in the add-in pane (Fig. 4.):

ADD-IN ERROR
This add-in could not be started. Close this dialog to ignore the problem or click "Restart" to try again.

670-4a
Fig. 4. The signature preview does not launch.

This issue might occur if Protected Mode is disabled in your Internet security settings in Windows. To solve this problem, try the following:

  1. Launch Internet Explorer, click the Tools button and select Internet options.

    Tip

    You can also access these settings from the Windows Control Panel or by opening the Start menu, typing Internet options and pressing Enter.

  2. Go to the Security tab and select the Internet (default) zone.
  3. Select the Enable Protected Mode checkbox, as shown in Fig. 5.

670-5
Fig. 5. How to enable Protected Mode in the Internet zone.

  1. Restart Outlook (and Internet Explorer, if necessary).
  2. If the problem still persists, try enabling the Protected Mode in the Restricted sites zone and restarting Outlook.

CodeTwo domain is blocked by antivirus software

To display a preview of the signature, CodeTwo Email Signatures for Office 365 Add-in needs to access two web locations:

Your antivirus software may be set to block connections to any domain outside its list of trusted domains. Make sure that you add the address of your geo location and of the add-in to trusted domains in your antivirus software.

Outlook version is not supported

CodeTwo Email Signatures for Office 365 Add-in works with all 32- and 64-bit versions of Outlook 2013 and newer. However, to use this add-in in Outlook 2013, you need to update Outlook 2013 to the newest version.

The add-in also works with Outlook 2016 for Mac and Outlook on the web (OWA).

A detailed list of requirements is available in the User’s manual.

The add-in pane is not pinnable

By default, the CodeTwo Email Signatures for Office 365 Add-in pane disappears every time you compose another email and you have to open the add-in from the ribbon to see the signature preview. To avoid this and keep the add-in pane open, you need to pin it to your Outlook via the button shown in Fig. 6.

ESIG for O365 add-in pinning
Fig. 6. Use the highlighted button to pin/unpin the signature preview pane in Outlook.

The availability of the option to pin add-ins depends on your Outlook version. If you don't see the pin button (Fig. 6.), you might need to update Outlook.

Info

Pinnable add-ins are available in the Click-to-Run versions of Outlook 2016 (build 7668.2 or later for users in the Current or Office Insider Channels, build 7900.x or later for users in Deferred channels). Learn more