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Home > English site > Articles > Add-ins do not load

Excel add-ins fail to load


Lately (I wrote this page on August 17, 2016) I've been getting reports from people complaining that they can no longer use add-ins. In this article I describe the problem and a solution.

The problem

Even though an add-in has been "installed" into Excel using the Add-ins dialog its userinterface does not show. This is that dialog:

Add-ins dialog of Excel

As you can see, some add-ins are checked. But sometimes the user-interface of an add-in fails to display. In fact, the add-in file will not open in Excel at all, even if you try from Windows Explorer, or from File, Open from within Excel. Without any error message.

The cause

A recent Office Security update has caused any file downloaded from the internet (so this includes add-ins) to be marked as Blocked. Even if those files were in a zip container, they are marked as blocked. And Excel will simply not open them.


Unblock the files! Like so:

1. Copy the file from the zip file to any folder

2. Right-click the file and choose properties:

Select file properties

3. Click the Unblock button:

Click Unblock

Other resources

If you have a folder full of blocked files, this page describes a way to unblock all of them using Powershell.

And a great article by fellow-MVP Jon Acampora: Excel Add-in Ribbon Disappears After Installation.

This article describes the mechanics of the problem very well:


All comments about this page:

Comment by: Patrick Matthews (8/17/2016 7:48:59 PM)

Blocking all downloaded files by default? That seems rather heavyhanded...


Comment by: Jan Karel Pieterse (8/18/2016 6:20:49 AM)

Hi Patrick,

I'm not sure yet whether it is all files, or just add-ins. I have mixed results when testing.


Comment by: Gunthor (10/19/2016 10:43:36 AM)

I've been looking for this answer for 2 months...
M A N Y T H A N K S :-)


Comment by: Ralph (2/7/2017 4:00:17 PM)

THANK YOU!!! I've been searching for this solution for a long, long-time!


Comment by: Wei (2/17/2017 7:37:12 AM)

I tried, but still failed, I also tried to update the regedit, move the dll file to a safe location. Almost feel crazy.......


Comment by: Jan Karel Pieterse (2/20/2017 9:57:33 AM)

Hi Wei,

The article is about Excel-based add-ins (xla and xlam files), not about dll files.


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