Excel 2016 stopped loading .xlam Excel Addins after security update from 12-nov-2024

Question

Hello,

After receiving an update for Excel 2016 a client of my reported that .xlam Excel Addins fail to load when you start Excel.

Note that the first letter from the path is missing in this case the C for the drive letter (because the .xlam file is placed in its own folder).

When you have a .xlam file in the default folder '%APPDATA%/Microsoft/AddIns' then it will remove the first letter of the name of the .xlam file itself.

Note, even a very simple .xlam file with just one VBA module and a macro only showing a message box will fail to load with the same error.

Also I did add the folder to trusted locations, but still Excel would not load .xlam files when started.

Please reply if you have any information for me, many thanks in advance.

***Microsoft 365 and Office / Excel / For business / Windows***

Answer 1

Dear E.J. Oskam，

Welcome to Microsoft Community.

We understand that your Excel file notifies you to load the .xlam Excel plug-in.

According to your description, you mainly have problems when using Excel and you have tried to add the folder path to the trusted location but it did not alleviate your problem.

Usually, .xlam format files contain customized macros or VBA formula information to help you improve your work efficiency, but this operation has corresponding requirements for account and program detection during operation.

Information about macro files needs to be explained to you:

Problems related to macros and VBA require more professional technical information to help you solve them. I suggest you try to seek help in Microsoft learn (English only), where there are more experts in related fields who can provide you with better solutions.

It is designed to support advanced users like you. Many users prefer to ask questions and get more professional responses through this section.

Here is a link to a forum where you can raise specific situations and share your ideas for solving problems.

Excel Management - Microsoft Q&A

Microsoft 365 - Microsoft Q&A 

At the same time, in order to troubleshoot the operation of your Office program, you can also try the following operations:

Registry reset office

(Before resetting, please make sure all your Office files have been backed up and saved. If you use OneNote and Outlook, you need to make sure that your notes and emails are backed up to avoid file loss. At the same time, resetting will put your Office program in its initial form. The personalized settings you set need to be saved first)

After resetting, you need to log in to Office again with your Microsoft account.

Press Windows + R, enter: regedit in the run box that opens, and press Enter.

Locate the following key value and rename the Office folder (right-click it and select Rename, such as renaming Office to Officeold)

HKEY_CURRENT_USER\Software\Microsoft\Office

Then reopen the file to try the effect.

Disclaimer: Generally, modifying registry subkeys or work group is intended for advanced users, administrators, and IT Professionals. It can help fix some problems, however, serious problems might occur if you modify the registry incorrectly. Therefore, make sure that you follow these steps carefully. For further protection, back up the registry before you modify it. Then, you can restore the registry if a problem occurs. For more information about how to back up and restore the registry, clickHEREto view the article.

Best regards

Zenobia.Z | Microsoft Community Support Specialist

Answer 2

Hello,

Our users are facing the same issue since a recent excel update... Temporarily, adding a space at the beginning of the key value in the registry fixes the error...

(Sorry for not illustrating with a screenshot, I would like to, but I get a "not found" error every time I try)

Answer 3

Hello Jerome Br.

Thanks for your reply, we did apply the workaround and .xlam Excel Add-in files are loaded by Excel 2016 again.

Answer 4

@Microsoft Excel 2016 bug introduced by the 12-november-2024 update

https://support.microsoft.com/en-us/topic/description-of-the-security-update-for-excel-2016-november-12-2024-kb5002653-189190cb-3ae5-47ac-b85a-ca9815cff793

The steps below describe a workaround, so that .xlam Excel Add-in workbooks are loaded again without an error message.

1# In the Windows Registry lookup the following key

HKEY_CURRENT_USER\Software\Microsoft\Office\16.0\Excel\Options

2# For each of your .xlam Excel Add-ins you find a REG_SZ entry with a name OPEN or OPEN1 etc...

3# Dubble click the entry and insert an extra character (space) before the drive letter

Answer 5

Hi

I found the same issues for xla add-ins too after installing the November update on an RDS server.

If you look at the path of the addin in the registry

HKEY_CURRENT_USER\Software\Microsoft\Office\16.0\Excel\Options

For each of the OPEN entries, I added the additional character ie "c:\excel\addin.xla" became "cc:\excel\addin.xla" and this has resolve the issue.

Seems odd that Microsoft are releasing updates for an unsupported office suite?

regards

Matt