All Office add-ins broken after Windows update

**All Office add-ins broken after Windows update — "Access denied to catalog" on Microsoft 365 Family (Word, Windows 11 Pro)**

All Office add-ins stopped working on my machine this week, immediately following a Windows update. They had been working normally the week before.

**Symptoms**

1. Home > Add-ins > More Add-ins > My Add-ins returns: **"Access denied to catalog."**

2. Attempting to load any add-in returns: **"ADD-IN ERROR — You don't have permission to use this add-in. Contact your system administrator to request access."**

3. Status bar intermittently shows: **"Error loading add-ins — One or more add-ins failed to load."**

This affects **every** add-in, not one publisher. I first noticed it with Claude for Microsoft 365, but no add-in from any vendor will load, and the catalog itself won't enumerate.

**Environment**

- Microsoft 365 Family (consumer subscription — there is no tenant and no administrator to contact)

- Windows 11 Pro

- Microsoft® Word for Microsoft 365 MSO (Version 2608 Build 16.0.20326.20072) 64-bit

- Microsoft account uses a custom domain address

**Troubleshooting already completed — please don't re-suggest these**

- Privacy settings verified: "Turn on all connected experiences," "Experiences that analyze your content," and "Experiences that download online content" are all enabled and **not** greyed out

- Cleared the add-in cache at %LOCALAPPDATA%\Microsoft\Office\16.0\Wef\

- Signed out of and back into the Microsoft account inside Word

- Office fully updated via File > Account > Update Options

- Refreshed the Admin Managed tab in the add-ins pane

- **Online Repair of Microsoft 365 completed**, followed by a reboot — error persists on a brand new blank document

- Confirmed no work or school account under Settings > Accounts > Access work or school

**What I'm asking**

Since a clean reinstall of the client did not change the behavior, this looks service-side rather than local. Specifically:

1. Is there a known regression in the recent Windows/Office update affecting the add-in catalog request on consumer subscriptions?

2. "Access denied to catalog" implies an identity or entitlement check failing upstream. Is there a way to see what identity the desktop client is actually presenting to the catalog service?

3. My Microsoft account is a custom-domain address. If that domain has ever had a Microsoft 365 tenant associated with it, could the client be resolving my identity against that tenant and inheriting its Office Store policy, despite my license being Family?

I contacted Microsoft Support by chat; the agent confirmed the issue appears broader than a single add-in and referred me here.

Happy to provide screenshots, build numbers, or logs. Thanks in advance.