Add-ins issue

Question

Add-ins issue

Jogleen Calipon 30

I do have two Microsoft accounts. One for work and one for personal use. My work account Excel add-ins work perfectly fine. However, my personal account add-ins are not. I use a Mini Calendar and Date Picker add-in primarily what I noticed before experiencing this issue is it first prompts me to accept the terms, after accepting the terms, it says ADD-IN ERROR. Is this a known issue? If my work account is the culprit, why does it work perfectly fine? I already tried a lot of TS steps such as clearing my registry but still not resolving the issue. I have disabled my anti-virus as well but still having the same results

reg delete "HKCU\SOFTWARE\Microsoft\Office\16.0\WEF" /f
reg add "HKCU\SOFTWARE\Microsoft\Office\16.0\WEF" /v "UseOsfWebHost" /t REG_DWORD /d 1 /f

Is there anyone who experiences the same problem? What TS did you take so I can try to replicate it. All other Add-ins did not work either. User's image

Jogleen Calipon 30 Reputation points

2026-05-31T00:45:38.0033333+00:00

What works for me so far is removing the add-ins and logging out from the account. Once the account has been logged out, add the add-ins and log back in. This is a very weird workaround. Not going to lie about it. The only caveat about this is every time you open the file, you need to redo it all over. This needs to be fixed hopefully sooner

Answer accepted by question author

EmilyS726 270.3K Independent Advisor

Hello,

I believe this may be a widespread issue. I am seeing reports from users in different locales experiencing the same problem. It seems to affect add-ins in general when using the desktop version of the app.

I am experiencing the same issue on my end as well. I have not found any official Microsoft announcement about this yet, but at this point, it does not appear to be something you can fix locally. We may need to wait for Microsoft to address it on their end.

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Jogleen Calipon 30 Reputation points

2026-05-31T00:45:38.0033333+00:00

What works for me so far is removing the add-ins and logging out from the account. Once the account has been logged out, add the add-ins and log back in. This is a very weird workaround. Not going to lie about it. The only caveat about this is every time you open the file, you need to redo it all over. This needs to be fixed hopefully sooner

Answer 1

The error shown in the screenshot ("You don't have permission to use this add-in. Contact your system administrator.") is a known class of issue with Office Add-ins and is typically caused by how add-ins are configured for the signed-in account/tenant, not by the add-in itself.

From the context provided:

Errors like this are usually due to Microsoft 365 tenancy or catalog configuration that prevents acquisition or execution of Office Store add-ins. In such cases, the add-in information box or task pane error is expected and users are instructed to contact their Microsoft 365 administrator.
There is also a specific known issue for centrally deployed add-ins in certain Office builds where users see the same message ("You don't have permission to use this add-in"). A fix is being rolled out, and in the meantime the recommended workaround is to refresh admin-managed add-ins or have an admin force a refresh via a registry key.

Because the work account add-ins function but the personal account does not, the most likely explanations supported by the context are:

The personal account’s tenant or catalog configuration is blocking access to the Office Store or specific add-ins, which leads to the permission error.
If the add-in is centrally deployed (admin-managed) and the Office build is affected by the known issue, the catalog may need to be refreshed for that account.

Actions supported by the context:

In Excel, open Home → Add-ins → More add-ins → Admin Managed, then select Refresh in the top-right. After refresh, try opening the add-in again.
If the add-ins are centrally deployed and an IT admin is available, the admin can force a refresh by creating the registry key HKCU\Software\Microsoft\Office\16.0\WEF\TrustedCatalogs\ClearInstalledExtensions with DWORD = 1 for the affected profile, then having the user restart Office and test again.
If the error continues, the account’s Microsoft 365 administrator needs to review add-in and Office Store settings for that tenant, because configuration-level restrictions are a documented cause of these permission errors.

Registry changes already attempted (such as UseOsfWebHost) are not mentioned in the context as a fix for this scenario, whereas catalog refresh and tenant configuration checks are.

References: