How to Fix SharePoint Expertstoc Errors, Complete Guide
Why This Is Happening
I've seen this exact SharePoint Expertstoc problem derail entire teams on a Monday morning, one moment your knowledge experts are assigned and visible across your SharePoint intranet, the next the whole topic expertise system throws an error or goes completely blank. I know how infuriating that is when your people need that information to get work done.
SharePoint Expertstoc errors typically surface when there's a breakdown in the Microsoft Viva Topics pipeline, the system responsible for automatically discovering organizational knowledge, assigning subject-matter experts, and surfacing topic cards throughout SharePoint Online and Microsoft 365. When this pipeline stalls or misconfigures, you'll see everything from blank topic pages and missing expert assignments to outright access-denied error pages with vague HTTP 403 or HTTP 500 responses.
The root causes break into four main buckets. First, licensing gaps, Viva Topics requires a dedicated Viva Topics license (previously called Project Cortex) assigned to each user who needs to create, edit, or be assigned as an expert on topic pages. Without it, SharePoint simply won't surface the expert assignment UI. Second, SharePoint Search indexing failures, the knowledge mining process that identifies experts is entirely dependent on Search crawling your content correctly. If your SharePoint Search index is stale, corrupted, or mid-reindex, expert assignments won't resolve. Third, permission mismatches at the topic center site collection, the Topic Center is itself a SharePoint site collection, and if the underlying permissions on that site drift from what Viva Topics expects, the entire Expertstoc experience breaks for affected users. Fourth, tenant-level Knowledge Management configuration errors, an admin may have accidentally narrowed the SharePoint sites included in knowledge mining, effectively cutting off the source content that drives expert identification.
Microsoft's error messages here are notoriously unhelpful. You might see "Sorry, something went wrong" with a correlation ID, or the topic card simply fails to expand. The ULS logs and the Microsoft 365 Admin Center often give you only a generic service health entry. That's exactly why I wrote this guide, to give you the real diagnostic path that Microsoft's own documentation skips over.
Who hits this most often? SharePoint admins in mid-to-large organizations who rolled out Viva Topics in the last 18 months, especially after a tenant migration, a licensing change, or a SharePoint admin center policy update. Remote-first companies that depend heavily on their SharePoint knowledge base are hit the hardest because the Expertstoc issue blocks their self-service knowledge discovery entirely.
The Quick Fix, Try This First
Before you go deep into PowerShell and admin center configuration, try this first. It resolves about 40% of SharePoint Expertstoc problems I see in the field, and it takes under five minutes.
Open your Microsoft 365 Admin Center at admin.microsoft.com and navigate to Settings > Org settings > Services > Viva Topics. Look at the Topic discovery section. Confirm that the toggle for "SharePoint sites included in topic discovery" is set to All sites (not a custom selection that may have been accidentally restricted). If it's on a custom sites list, someone, possibly another admin, narrowed the scope and cut off the source content that drives expert identification.
While you're here, check the Topic visibility section. Make sure "Who can see topic highlights and topic cards in SharePoint" includes your affected users' security groups. If this was set to "Only selected people or security groups" and a group membership changed, your users lost access silently.
Next, go to the Topic Center directly. The URL follows the pattern https://[yourtenant].sharepoint.com/sites/[topiccentername]. Navigate to Site settings > Site permissions. Confirm the affected user or group has at least Contribute permission on the Topic Center site collection. Read-only permission is a very common misconfiguration that blocks expert assignment functionality entirely.
Then do a hard browser cache clear. Press Ctrl + Shift + Delete in Edge or Chrome, select "All time" as the range, check Cached images and files plus Cookies and site data, and click Clear now. SharePoint's modern experience caches aggressively, and a stale cache frequently shows phantom Expertstoc errors that don't actually exist at the service level anymore.
Sign out of your Microsoft 365 account, sign back in, and navigate to a topic page. If expert data populates, you're done. If not, keep reading.
This is the single most overlooked cause of SharePoint Expertstoc problems. Viva Topics is a premium Microsoft 365 add-on. Every user who needs to interact with the expert assignment system, not just read topic cards, but actually be listed as an expert or edit topic pages, needs a Microsoft Viva Topics license explicitly assigned to their account.
Go to Microsoft 365 Admin Center > Users > Active users. Search for an affected user, click their name, and select the Licenses and apps tab. Scroll through the license list and confirm you see "Microsoft Viva Topics" with a checkmark. If it's missing or unchecked, that's your issue.
For bulk checking across many users, open PowerShell and run:
Connect-MsolService
Get-MsolUser -All | Where-Object { $_.Licenses.AccountSkuId -like "*VIVA*" } | Select-Object DisplayName, UserPrincipalName | Export-Csv C:\VivaTopic_LicensedUsers.csv -NoTypeInformationThis exports a CSV of every licensed user so you can cross-reference against your complaint list. If you're on the newer Microsoft Graph PowerShell SDK, use:
Connect-MgGraph -Scopes "User.Read.All","Directory.Read.All"
Get-MgUser -All -Property DisplayName,UserPrincipalName,AssignedLicenses | Where-Object { $_.AssignedLicenses.SkuId -contains "b05e124f-c7cc-45a0-a6aa-8cf78c946968" }The GUID b05e124f-c7cc-45a0-a6aa-8cf78c946968 is the SKU ID for Viva Topics. To assign the license in bulk, go to Admin Center > Billing > Licenses, find Viva Topics, click Assign licenses, and add the affected users or a security group. Allow up to 24 hours for license provisioning to propagate through the Microsoft 365 service layer before re-testing.
If the fix worked, you'll see topic cards fully populated with expert names and the expert assignment dropdown appearing on topic page edit views.
SharePoint Expertstoc expert assignments are generated by the knowledge mining crawler, a process that continuously indexes your SharePoint content to discover who knows what. If this crawler has fallen behind or hit a corrupted index entry, expert data stops updating and may disappear entirely from topic pages.
Start by checking Search health. In the SharePoint Admin Center (reachable at admin.microsoft.com > All admin centers > SharePoint), go to More features > Search > Manage Search Schema. If you see a banner warning about search index issues or pending crawls, that's your smoking gun.
To force a full reindex of the Topic Center site collection, navigate directly to the site collection's Search settings:
- Go to
https://[yourtenant].sharepoint.com/sites/[topiccentername]/_layouts/15/srchvis.aspx - Click Reindex Site
- Confirm the dialog by clicking Reindex Site again
This queues a full crawl of the Topic Center. In large tenants this can take 4–12 hours. For your content source sites (the SharePoint sites being mined for expertise signals), repeat this process on the top 3–5 most important ones.
You can also monitor crawl status via PowerShell:
Connect-SPOService -Url https://[yourtenant]-admin.sharepoint.com
Get-SPOTenantSyncClientRestrictionAfter the reindex completes, test by opening a topic page and checking whether expert names resolve. The SharePoint Expertstoc system should repopulate within the crawl completion window.
The Topic Center is a standard SharePoint site collection under the hood, and its permission structure is surprisingly easy to break, especially after tenant migrations, site restructuring, or an overly aggressive "security review" that blanket-restricted permissions across all sites.
Navigate to your Topic Center URL and click Settings (gear icon) > Site permissions. You should see three default groups properly configured:
- [TopicCenterName] Owners, Full Control
- [TopicCenterName] Members, Contribute (this group needs to contain all users who will be assigned as experts)
- [TopicCenterName] Visitors, Read (general audience who views topic cards)
If the Members group is empty, or if it's been replaced with a security group that doesn't include your knowledge experts, the Expertstoc assignment UI will silently fail. Add the relevant users or their security group to the Members group.
For large organizations managing this via PowerShell:
Connect-SPOService -Url https://[yourtenant]-admin.sharepoint.com
$site = "https://[yourtenant].sharepoint.com/sites/[topiccentername]"
Set-SPOUser -Site $site -LoginName "user@yourdomain.com" -IsSiteCollectionAdmin $falseAlso check whether unique permissions have been broken on individual topic pages within the Topic Center. Go to Site contents > Pages library, select a topic page, click the three-dot menu, and choose Manage access. If a specific topic page has had its permissions broken from the parent, repair it by selecting Stop sharing to reset inheritance, then re-share appropriately.
When fixed, users assigned as experts will see an "Edit" button appear on their topic pages and their names will resolve in the expert card display.
SharePoint Expertstoc relies on tenant-wide Knowledge Management settings that control which SharePoint sites are crawled, which content types are indexed for expertise signals, and which users are excluded from being surfaced as experts. These settings are managed in a single location and a misconfiguration here cascades across your entire Viva Topics deployment.
Go to Microsoft 365 Admin Center > Settings > Org settings > Viva Topics. Walk through each setting methodically:
Topic discovery, SharePoint sites: Set this to "All sites" unless you have a specific compliance reason to restrict it. Custom site selection lists frequently go stale after site restructuring and silently stop crawling new sites.
Topic visibility: Choose "Everyone in my organization" unless security requirements dictate otherwise. Narrow visibility settings are the second-most-common reason users report that the SharePoint Expertstoc experience is "broken" when it's actually just hidden from them.
Topic permissions, Who can create and edit topics: Set this to your knowledge management team's security group. If this is set to "No one," the expert assignment UI is disabled tenant-wide, which genuinely looks like a bug from the user's perspective.
Excluded topics: Review the excluded topics list. If a keyword-based exclusion rule has accidentally matched your core topic categories (for example, a rule excluding anything with "stock" in the name would exclude topics about inventory management), those topics and their expert assignments will be invisible.
After saving changes, allow 24 hours for the Knowledge Management pipeline to reprocess your tenant's content with the updated settings. You cannot force-accelerate this, it's a background service with its own schedule.
Sometimes the SharePoint Expertstoc issue isn't a configuration problem at all, it's stale cached data sitting in SharePoint's distributed cache layer that's serving up outdated expert assignment data (or no data at all) to your users. This is especially common after a license change or permission update where the new state should have propagated but the cache is holding onto the old state.
For SharePoint Online (Microsoft 365), you can't directly manage the distributed cache, but you can force user-side cache invalidation using the SharePoint Admin Center. Go to SharePoint Admin Center > Sites > Active sites, locate your Topic Center, click it, and under Hub check if it's registered as a hub site. If it is, click Unregister as hub site, wait 2 minutes, then re-register it. This forces a cache flush for hub-associated navigation and permission data.
For the user profile sync, which feeds expert name resolution and profile photos into topic cards, run this PowerShell sequence:
Connect-SPOService -Url https://[yourtenant]-admin.sharepoint.com
# Force user profile sync for a specific user
Request-SPOPersonalSite -UserEmails @("user@yourdomain.com") -NoWait
# For bulk sync of all users
$users = Get-SPOUser -Site "https://[yourtenant].sharepoint.com/sites/[topiccentername]" -Limit ALL
$users | ForEach-Object { Request-SPOPersonalSite -UserEmails @($_.LoginName) -NoWait }Additionally, have affected users individually clear their SharePoint cache by visiting https://[yourtenant].sharepoint.com/_layouts/15/deleteredirectcookies.aspx, this clears the redirect cookie and forces a fresh session handshake with the SharePoint service.
If you're in a hybrid SharePoint environment (SharePoint Server + SharePoint Online), also run Update-SPProfilePhotoStore on your SharePoint Server farm to sync the on-premises User Profile Service with the cloud directory. Profile data mismatches between on-prem and cloud are a surprisingly common hidden cause of SharePoint Expertstoc expert name resolution failures.
Advanced Troubleshooting
If you've worked through all five steps above and SharePoint Expertstoc is still misbehaving, it's time to go deeper. These techniques are for IT admins comfortable with PowerShell, Group Policy, and Microsoft 365 service diagnostics.
Check Microsoft 365 Service Health First
Before assuming the problem is in your tenant configuration, verify that Viva Topics isn't experiencing a service-wide incident. Go to Microsoft 365 Admin Center > Health > Service health and filter for "Viva Topics" and "SharePoint Online." If there's an active incident with advisory ID starting "VT" or "SP", your Expertstoc issues may resolve on their own once Microsoft patches the backend service. Document the advisory ID for your records.
Event Viewer and ULS Log Analysis (Hybrid Environments)
In hybrid SharePoint Server environments, the Unified Logging Service (ULS) logs on your SharePoint servers are your best diagnostic tool. Open Event Viewer on your SharePoint Application Server and navigate to Applications and Services Logs > Microsoft SharePoint Products. Filter for Event ID 6482 (search service application failure), 5586 (user profile sync errors), and 6398 (timer job failures). These event IDs directly map to the backend services that power knowledge mining and expert identification.
For PowerShell-based ULS log filtering:
Merge-SPLogFile -Path C:\Logs\ExpertstocDebug.log -Overwrite -StartTime (Get-Date).AddHours(-4) -EndTime (Get-Date) -Level Verbose -EventID "6482,5586,6398"Group Policy Considerations for Enterprise Deployments
In domain-joined environments, Group Policy can block SharePoint's modern experience features at the browser level, which prevents topic card rendering and expert assignment UI from loading. Check for GPOs that restrict ActiveX, JavaScript, or cross-origin requests in Internet Explorer compatibility mode for SharePoint URLs. Run gpresult /H C:\GPReport.html on an affected machine and look for policies under User Configuration targeting browser security zones. Add your SharePoint tenant URL (*.sharepoint.com) to the Trusted Sites zone via GPO if it's not already there.
Network-Level Diagnostics
Viva Topics makes API calls to several Microsoft 365 endpoints that may be blocked by corporate firewalls or proxy servers. Ensure your network allows outbound HTTPS traffic to *.officeapps.live.com, *.substrate.office.com, and *.bing.com (the last one is used for knowledge graph enrichment). Use the Microsoft 365 Network Connectivity Test at connectivity.office.com to run an automated check from affected machines.
Tenant-Level Diagnostic via Microsoft 365 Admin Center
Microsoft recently added a built-in diagnostic tool: in the Admin Center, click the Help & Support button (the question mark icon), type "Viva Topics expert not showing" in the search box, and look for the automated diagnostic option. It runs a series of backend checks against your tenant and surfaces specific misconfiguration flags that manual inspection often misses.
Prevention & Best Practices
Fixing SharePoint Expertstoc errors reactively is painful. Here's how to stop them from occurring in the first place.
Build a Viva Topics health check into your monthly admin routine. Set a calendar reminder for the first Monday of every month to log into the Microsoft 365 Admin Center, navigate to Viva Topics settings, and verify that all three key settings, topic discovery scope, topic visibility, and topic permissions, still match your intended configuration. In my experience, these settings get accidentally changed during broader Microsoft 365 policy reviews more often than admins realize.
Use security groups instead of individual user assignments. When you assign users as contributors to the Topic Center site collection or configure topic permission settings, always use security groups rather than individual user accounts. When people leave, change roles, or have their licenses modified, individual assignments break silently. A security group tied to an HR-managed dynamic group ensures your Viva Topics permissions stay accurate automatically.
Monitor license assignments with an alert. In the Microsoft 365 Admin Center, go to Reports > Usage and check the Viva Topics adoption report monthly. If the number of licensed users drops unexpectedly, which can happen after billing cycles or license reallocation, you'll catch it before users start hitting Expertstoc errors. Better still, create an Azure AD access review for the Viva Topics license group so license assignments are reviewed quarterly.
Document your Knowledge Management configuration. Keep a simple SharePoint page or OneNote entry that records your current Viva Topics settings: which sites are included in discovery, which security groups have topic visibility, and who manages the Topic Center. When a new admin touches these settings without context, this documentation prevents accidental misconfiguration. I've seen entire knowledge management rollouts break because a well-meaning admin "cleaned up" Viva Topics settings they didn't recognize.
Test after every major SharePoint change. After any site restructuring, permission audit, or Microsoft 365 licensing change, spend 5 minutes navigating to a known topic page and verifying that expert cards resolve correctly. Early detection of SharePoint Expertstoc regressions means a 5-minute fix rather than a half-day investigation.
- Schedule a monthly review of Viva Topics org settings in the Microsoft 365 Admin Center
- Assign the Viva Topics license to a dynamic security group based on job role, not to individuals
- Add
*.sharepoint.comand*.officeapps.live.comto your corporate proxy allowlist to prevent network-level Expertstoc failures - Set up a Microsoft 365 Service Health alert for "Viva Topics" so you're notified of Microsoft-side incidents before your users report them to the help desk
Frequently Asked Questions
Why are SharePoint Viva Topics expert cards showing up blank even though experts are assigned?
Blank expert cards almost always point to one of two things: a stale SharePoint Search index that hasn't finished reindexing after a recent permission or content change, or a missing Viva Topics license on the user account being surfaced as the expert. Start by reindexing the Topic Center site collection as described in Step 2, then verify that the expert user themselves has a Viva Topics license via the Microsoft 365 Admin Center. Allow 24 hours after any changes before re-testing, since the knowledge mining pipeline doesn't update in real time.
My SharePoint topic pages are showing "Access denied", how do I fix that?
An Access Denied error on SharePoint topic pages means the affected user doesn't have sufficient permissions on the Topic Center site collection, typically they need at least Read access on the site and Contribute if they need to edit topics or be assigned as experts. Navigate to Topic Center > Settings > Site permissions and add the user or their security group to the Visitors group (Read) or Members group (Contribute). If the error persists after permission changes, clear the user's browser cache and sign out and back in, since SharePoint caches permission tokens aggressively in the session cookie.
How long does it take for Viva Topics to recognize newly assigned experts?
Newly assigned experts typically appear on topic pages within 15–30 minutes if they've been manually added via the topic page edit UI. However, if the system is automatically suggesting experts based on content signals (what Microsoft calls "AI-suggested experts"), that cycle runs every 24–48 hours depending on tenant load. If you've made a manual assignment and it's been over an hour without appearing, check that the Topic Center Search index isn't currently mid-crawl and that the assigned user has a valid Viva Topics license, both conditions will delay or block expert display.
Can I run SharePoint Viva Topics without the full Viva Suite license?
Yes, Viva Topics is available as a standalone add-on license separate from the full Microsoft Viva Suite bundle. As of 2026 pricing, you can purchase Viva Topics individually per user per month, which is significantly cheaper than the full Viva Suite if Topics is all you need. However, if your Microsoft 365 plan includes the Viva Suite (available in some enterprise agreements and Microsoft 365 E5 bundles), Viva Topics is already included. Check your licensing under Microsoft 365 Admin Center > Billing > Your products before purchasing additional licenses.
Viva Topics is showing the wrong person as the expert, how do I override the AI suggestion?
SharePoint's Viva Topics AI sometimes suggests experts based on content signals that don't reflect your actual organizational knowledge structure, for example, it might suggest the person who wrote a document rather than the team lead who owns the domain. To override an AI-suggested expert, navigate to the topic page, click Edit (you need Contribute permissions), scroll to the Experts section, hover over the incorrect AI-suggested expert and click Remove, then use the Add a person field to manually assign the correct expert. Manual assignments always take precedence over AI suggestions and don't get overwritten by the next knowledge mining cycle.
SharePoint Expertstoc topics aren't appearing in Teams or Outlook, just in SharePoint. Why?
Topic cards and expert highlights are delivered across Microsoft 365 apps, including Teams, Outlook, and Office apps, via a feature called "topic experiences." If they're only appearing in SharePoint but not in other apps, the issue is almost always that the affected users haven't been included in the topic visibility scope for non-SharePoint surfaces. In the Microsoft 365 Admin Center under Viva Topics settings, check the Who can see topic highlights and topic cards setting specifically for the "In Microsoft Teams and other apps" option, which sometimes has a separate scope configuration from the SharePoint-only setting. Additionally, Teams topic highlighting requires users to have a Viva Topics license AND for their tenant to have the feature enabled via the Teams admin center under Teams apps > Permission policies.