Andrei Smolin

Problems with ADXTaskPane are solved in Add-in Express for Office v.9

Hello Developers,

Recently, our mail boxes became overwhelmed with a flow of reports describing how Add-in Express panes appear outside the host application’s window. This is a manifestation of how the code calling the SetParent Windows API function can be incompatible with the recent Windows API change supported by Office 2016: Microsoft introduced DPI contexts and related API functions to let you get/set the current context. Now, to call SetParent, you must set the DPI context corresponding to the DPI context of the target window. Version 8 of Add-in Express for Office (.net and VCL) doesn’t set the required DPI context when embedding your ADXTaskPane in the hosts’ windows and this is the direct cause of the issue. Affected are the Add-in Express 8 based add-ins running in Office 2016 on Windows 10.

A workaround is to choose the Optimize for compatibility option in Display Settings; see the status bar or File | Options | General. Select this option, restart the Office application and it will use the old Windows API. If Display Settings is missing, the only way for you is to switch to Add-in Express 9.

ADX.NET 9 and ADX.VCL 9 introduced only one feature: support for the Windows API changes above. You may be required to modify your code as we described in Add-in Express adds support for multiple monitors in Office.

Below is a download link for an installer of a sample add-in that demonstrates how an add-in based on Add-in Express 9 behaves in Excel, Word, PowerPoint and Outlook from Office 2000-2016.

Good luck!

Available downloads:

This sample add-in was developed using version 9.1 of Add-in Express for Office and .net:

Sample add-in project (VB.NET and C#)


  • JP says:

    So for those of us who do not (yet) have a v9 license, given the significant disconnect in basic functionality, we have to purchase the upgrade to use v9?

    It’s been nice to avoid that very reality over time. I recognize upgrading to v9 for 2019 support makes sense – but this isn’t a minor issue and one reason to use the add-in rather than direct programming.

  • Andrei Smolin (Add-in Express Team) says:

    Hello JP,

    Thank you for your feedback. Sorry, we won’t be able to change code in older Add-in Express versions because we only maintain the current version of the code base.

  • Sam says:

    This issue occurs on single monitors as well.

  • Andrei Smolin (Add-in Express Team) says:

    It relates to Windows/Office supporting multiple monitors.

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