Fix Dynamics 365 Remote Assist Not Working
Why Dynamics 365 Remote Assist Stops Working
I've seen this exact situation play out on dozens of enterprise deployments: a field technician puts on the HoloLens, launches Dynamics 365 Remote Assist, and either stares at a spinning authentication screen, gets dropped mid-call, or watches their video quality collapse into a pixelated mess while a remote expert squints at a blurry image of a broken machine part. The work stops. The frustration starts.
Dynamics 365 Remote Assist is a mixed reality collaboration tool designed for HoloLens. It lets frontline workers share their real-world view with remote experts , using spatial annotations, shared OneDrive files, and live video calls , without either person needing to be in the same location. When it works, it's genuinely impressive. When it doesn't, the failure modes are maddeningly vague.
The root causes almost always fall into one of four buckets. First: network misconfigurations. Remote Assist depends on a specific set of URLs and ports that many corporate firewalls quietly block. Because the app doesn't tell you "UDP port 3479 is blocked on your network", it just fails silently or degrades, you end up chasing ghosts. Second: Microsoft Entra authentication failures. The app requires a properly licensed Microsoft Entra account (what many IT admins still call an Azure Active Directory account), and if the license assignment is incomplete or the token refresh fails, you get login loops. Third: bandwidth and wireless band problems. The HoloLens has real network requirements that most people underestimate, and dropping the device onto a crowded 2.4 GHz guest Wi-Fi is a recipe for dropped calls. Fourth: deployment and provisioning errors, missed steps in the Microsoft 365 admin portal or Microsoft Store for Business that leave the device in a half-configured state.
None of this is your fault. Microsoft's error messages in Remote Assist are notoriously unhelpful, you're likely to see a generic "Something went wrong" or just a failed connection with no error code at all. This guide translates what's actually happening under the hood into concrete, actionable fixes.
I know this is frustrating, especially when it's blocking real work on a job site or in a manufacturing facility. Let's get it sorted. Browse all Microsoft fix guides →
The Quick Fix, Try This First
Before you go deep on network analysis or license audits, run through this checklist. In my experience, one of these three things fixes the problem for about 60% of cases.
Step one: verify the HoloLens is on a 5 GHz Wi-Fi band, not 2.4 GHz. Open the HoloLens Settings app, go to Network & Internet, tap the connected network, and confirm it's connecting to a 5 GHz SSID. If you only have one SSID in your environment that serves both bands, that's your first problem to solve, more on that in the Prevention section.
Step two: test raw connectivity to the Microsoft authentication endpoints. From a PC on the same network segment as the HoloLens, open a browser and navigate to https://login.microsoftonline.com. If that page loads, your firewall isn't blocking TCP 443 to the auth endpoints. If it doesn't load, or redirects to a proxy block page, that's your culprit.
Step three: sign out of Remote Assist and sign back in. On the HoloLens, open Remote Assist, select your account icon in the top right, choose Sign out, then sign back in with your Microsoft Entra credentials. A stale authentication token is a surprisingly common cause of connection failures, and a fresh sign-in clears it immediately.
If call quality is the issue rather than connectivity: check your current bandwidth. Microsoft's documentation is explicit, you need a minimum of 1.5 Mbps up and down for HD video calling at 1080p/30fps, and the optimal experience requires 4–5 Mbps up/down. On first-generation HoloLens hardware, even 4–5 Mbps may not fully deliver 1080p quality. Run a speed test from a device on the same SSID the HoloLens uses. If you're below 4 Mbps, that explains everything.
Remote Assist won't work without a properly assigned license, and the error you see when the license is missing looks identical to a network authentication failure. This is where a lot of IT admins waste hours chasing the wrong problem.
Sign in to the Microsoft 365 admin portal at admin.microsoft.com using your administrator account. Navigate to Users > Active users, then search for the user who's having trouble with Remote Assist. Click their name, then select the Licenses and apps tab.
Confirm that the user has a Dynamics 365 Remote Assist license assigned. If the toggle is off, turn it on and click Save changes. License propagation typically takes 5–10 minutes, but in some tenant configurations it can take up to 24 hours, so if you just assigned the license, wait before concluding it didn't work.
Also verify that the underlying Microsoft Teams license is active for this user. Remote Assist calls run over Teams infrastructure, and a missing or disabled Teams license will break calling even if the Remote Assist license is present.
If you're distributing the Remote Assist app to HoloLens devices through Microsoft Store for Business, confirm the app is assigned to the correct device group or user in the Store for Business admin portal. A common mistake is assigning the license at the tenant level but forgetting to push the app through Store for Business, the device never gets the install.
After confirming licenses are correct, have the user restart the HoloLens completely (not sleep, a full power cycle), then relaunch Remote Assist. You should see the sign-in screen populate with their account immediately if the Entra authentication is working.
This is the most common infrastructure-level fix, and it's the one your network team needs to be involved in. Dynamics 365 Remote Assist depends on multiple Microsoft services, each requiring its own set of endpoints to be reachable. If your corporate firewall is doing SSL inspection or blocking outbound UDP, Remote Assist will fail in ways that look like software bugs but are actually network blocks.
Here's the complete list of what needs to be open, drawn directly from Microsoft's requirements:
For Teams calling (the engine that powers Remote Assist calls), you need:
URLs: *.registrar.skype.com
*.teams.microsoft.com
Ports: UDP 3478, 3479, 3480, 3481The UDP ports are non-negotiable. If your firewall only allows TCP, Teams will attempt a TCP fallback, but call quality will degrade significantly, expect choppy audio, frozen video frames, and dropped calls. Open UDP 3478–3481 outbound from the network segment your HoloLens devices use.
For authentication (Microsoft Entra sign-in):
URLs: login.microsoft.com
login.microsoftonline.com
login.live.com
sts.windows.net
Port: TCP 443 (and TCP 80)For Dynamics services, SharePoint/OneDrive file sharing, and Microsoft Graph:
*.crm.dynamics.com TCP 80, 443
*.sharepoint.com TCP 80, 443
graph.microsoft.com TCP 80, 443
ecs.office.com TCP 80, 443
*.msftconnecttest.com TCP 80, 443Ask your network team to run a packet capture or firewall log review specifically for the IP range of your HoloLens devices. Look for blocked UDP flows to the Skype/Teams IP ranges, that's almost always the first thing to show up when Remote Assist calls won't connect. If you're in a US Government GCC environment, you also need to add the Office 365 GCC High endpoints and the Dynamics 365 US Government and Power Apps US Government endpoint lists to your allowlist.
The HoloLens is not a phone. It doesn't gracefully handle network congestion the way a smartphone does, and a shared, heavily-loaded Wi-Fi network will kill your Remote Assist experience even when raw bandwidth looks adequate on paper.
Microsoft explicitly recommends putting HoloLens devices on a dedicated SSID operating on the 5 GHz band only, with the 2.4 GHz band disabled on that SSID. This isn't optional guidance for high-stakes environments, it's the difference between a reliable call and a frustrating one.
Here's why: 2.4 GHz is a crowded spectrum. In a typical warehouse or factory floor, you're competing with Bluetooth devices, older IoT sensors, other Wi-Fi networks, and interference from machinery. 5 GHz has more available channels and less interference, which directly reduces jitter and packet loss, the two network factors that hurt video call quality the most even when bandwidth looks fine.
To check the current band on HoloLens: go to Settings > Network & Internet > Wi-Fi, tap the connected network name, and look at the network details. A 5 GHz connection will show channel numbers in the 36–165 range; 2.4 GHz channels run 1–14.
On your wireless access point or controller, create a new SSID specifically for mixed reality devices. Name it something identifiable like MR-Devices-5GHz. Configure it for 5 GHz only, use WPA2-Enterprise or WPA2-PSK (avoid WPA3 unless you've confirmed HoloLens firmware compatibility), and disable band steering on this SSID. Also enable MU-MIMO (Multi-User, Multiple Input Multiple Output) on the access point, this allows the AP to serve multiple devices simultaneously rather than time-slicing, which reduces latency for HoloLens video streams.
After switching the HoloLens to the new 5 GHz SSID, retest your Remote Assist call. If call quality improves but doesn't fully resolve, move on to measuring bandwidth with CQD.
When calls are connecting but quality is poor, blurry video, audio dropouts, lag on annotations, you need data, not guessing. Teams Call Quality Dashboard and Teams Call Analytics give you exactly that, and they're free tools already included in your Microsoft 365 subscription.
Call Analytics is for per-user, per-call investigation. To access it: open the Teams admin center at admin.teams.microsoft.com, go to Users > Manage users, find the user experiencing issues, select their name, then click the Meetings & Calls tab. You'll see a list of recent calls. Click any call to see detailed metrics: audio/video stream quality, packet loss percentage, round-trip latency, jitter in milliseconds, and the network path taken.
What you're looking for in these numbers:
Packet Loss: > 1% is problematic for video
Jitter: > 30ms will cause visible video artifacts
Round-trip: > 150ms will cause noticeable lag in annotations
Bandwidth: Sustained < 1.5 Mbps = degraded videoTeams CQD is for fleet-wide and trend analysis. Access it at cqd.teams.microsoft.com. Use the built-in Managed Networks reports to identify if the quality problem is specific to one building, one subnet, or one access point. If every HoloLens on a specific floor shows high jitter in CQD, that points to an AP configuration issue. If only one user's device shows poor quality while others on the same SSID are fine, the problem is more likely device-level or account-level.
Once you've identified the specific metric that's failing, whether it's packet loss, jitter, or bandwidth, bring those specific numbers to your network team. "Remote Assist calls are bad" is hard to act on. "HoloLens devices on subnet 10.20.5.x are seeing 4.2% packet loss and 80ms jitter on UDP flows to *.teams.microsoft.com" is actionable.
If none of the above resolves your issue, particularly if Remote Assist won't launch at all, crashes immediately after opening, or shows a blank screen, the problem may be a corrupted or incomplete app installation. A clean redeploy through Microsoft Store for Business usually fixes this.
First, on the HoloLens, remove the current installation. Go to Settings > Apps > App & features, find Dynamics 365 Remote Assist in the list, select it, and choose Uninstall. Confirm the uninstall. This removes the app and its local data cache, which sometimes contains corrupted authentication tokens or configuration state that prevents clean startup.
Next, in the Microsoft Store for Business admin portal, verify the app is still assigned to the device or device group. Navigate to Manage > Products & services, find Dynamics 365 Remote Assist, and confirm the license and device assignment are in place. If the assignment looks correct, toggle it off, save, then toggle it back on, this forces a resync of the assignment to the device management system.
On the HoloLens, open the Microsoft Store app and navigate to Downloads & updates. You should see Dynamics 365 Remote Assist queued for installation. If it doesn't appear within 10–15 minutes, go to Settings > Update & Security > Windows Update and check for device management policy updates, sometimes the Store for Business assignment propagates through the MDM channel rather than appearing in the Store app directly.
After reinstalling, restart the HoloLens before launching Remote Assist for the first time. Sign in with the user's Microsoft Entra credentials when prompted. If the license is correctly assigned and network endpoints are open, the app should authenticate and reach the main interface within 30–60 seconds.
Advanced Troubleshooting for Dynamics 365 Remote Assist
If you've worked through the steps above and still can't resolve the issue, you're likely dealing with an enterprise-specific configuration problem. These scenarios require deeper access, Group Policy, network infrastructure, or tenant-level settings.
Conditional Access Policies Blocking Sign-In
Microsoft Entra Conditional Access is a common silent killer of Remote Assist sign-ins in enterprise environments. If your tenant has a Conditional Access policy requiring compliant devices or enforcing MFA for specific app registrations, the HoloLens may be failing that policy check without surfacing a useful error. To investigate: in the Azure portal, go to Microsoft Entra ID > Sign-in logs, filter by the user's UPN, and look for failed sign-ins from the HoloLens device. The failure reason field will tell you exactly which Conditional Access policy is blocking access and why.
Common fixes: add an exclusion for the Dynamics 365 Remote Assist application registration, or add the HoloLens device to a compliant device group in Intune. The second option is better from a security posture standpoint.
Windows Notification Service (WNS) for Push Notifications
Remote Assist uses Windows Notification Service for certain push functions. If your network blocks WNS traffic, users may miss incoming call notifications while the app is in the background. Microsoft's documentation points to the Enterprise Firewall Configurations to Support WNS Traffic documentation for the specific IP ranges and endpoints. Ask your network team to cross-reference your firewall rules against those WNS requirements.
GCC and Government Cloud Environments
If your organization uses the US Government Community Cloud (GCC) or GCC High environment, the standard endpoint list is not sufficient. You must additionally add all endpoints from the Office 365 U.S. Government GCC High endpoints documentation, the Dynamics 365 US Government endpoint list, and the Power Apps US Government endpoint list. Missing any one of these produces authentication failures that look identical to a misconfigured license. Cross-reference each endpoint list against your firewall allowlist before concluding it's a software problem.
Event Viewer on Windows for Teams Client Issues
On a Windows PC running the Teams desktop app (which remote experts use to receive Remote Assist calls), Event Viewer can surface Teams client errors that don't appear in the UI. Open Event Viewer, navigate to Applications and Services Logs > Microsoft > Windows > DeviceSetupManager, and also check Application logs filtered by Source: Teams. Authentication errors, network timeouts, and Teams service connectivity issues all log here with specific error codes that you can reference against Microsoft's documentation.
Prevention & Best Practices for Dynamics 365 Remote Assist
Once you've resolved the immediate issue, the goal is to make sure it doesn't happen again, especially in operational environments where HoloLens downtime has real business impact.
Network readiness assessment before deployment. Before rolling out Remote Assist to a new facility or site, run a proper network readiness check from that site's wireless network. Use the Teams Network Assessment Tool (available from Microsoft) to test UDP connectivity to Teams endpoints, measure jitter and packet loss, and confirm bandwidth. Do this before devices arrive, not after.
Monitor with CQD proactively, not reactively. Set up CQD alerts for when call quality metrics drop below acceptable thresholds for your HoloLens user group. You want to know about a degraded access point or a network routing change before your field technicians start complaining, not after a shift of poor-quality calls.
Keep HoloLens firmware updated. HoloLens firmware updates often include networking stack improvements and Teams client updates that fix call quality issues. Set a regular cadence, at least monthly, to check for and apply Windows Holographic for Business updates via Settings > Update & Security > Windows Update on each device.
Document your endpoint allowlist and review it quarterly. Microsoft periodically updates the URL and IP range requirements for Teams and Dynamics services. Add a quarterly calendar reminder to cross-check your firewall allowlist against the current version of the Microsoft 365 endpoint list at endpoints.office.com. A single new endpoint that gets blocked quietly by your firewall can break Remote Assist calling without any obvious cause.
Plan for the December 31, 2026 end-of-support date. Microsoft has announced that Dynamics 365 Remote Assist will reach end of support on December 31, 2026. If you're mid-deployment or planning a new rollout, factor this timeline into your roadmap. The replacement path currently being positioned is Remote Assist functionality within Microsoft Teams Mobile, start evaluating that workflow now so you're not caught unprepared at end-of-year 2026.
- Create a dedicated 5 GHz-only SSID for all HoloLens and mixed reality devices, never share a band-steering SSID with general users
- Enable MU-MIMO on access points serving HoloLens devices to reduce per-device latency during multi-device sessions
- Schedule monthly firmware checks for all HoloLens devices via your MDM solution, outdated firmware is a persistent source of unexplained call failures
- Assign a secondary IT admin as a backup license manager in the Microsoft 365 admin portal, license expirations and assignment errors are often discovered only when a field tech can't log in on a job site
Frequently Asked Questions
Why does Dynamics 365 Remote Assist keep disconnecting mid-call?
Mid-call disconnections are almost always a network issue, not a software bug. The most common cause is insufficient sustained bandwidth, Remote Assist requires at least 1.5 Mbps up/down for HD video, and on a shared Wi-Fi network, that can dip below the threshold mid-call even if a speed test shows adequate bandwidth. Check whether the HoloLens is on a 5 GHz dedicated SSID, confirm UDP ports 3478–3481 are open outbound, and use Teams Call Analytics to review the specific call session for packet loss and jitter spikes. Packet loss above 1% consistently causes visible disconnections in video streams.
Remote Assist won't sign in on HoloLens, it just loops back to the login screen. What's wrong?
This is almost always either a missing license or a blocked authentication endpoint. First, go to the Microsoft 365 admin portal and confirm the user has a Dynamics 365 Remote Assist license actively assigned, not just a pending assignment. Second, verify that login.microsoftonline.com, login.microsoft.com, login.live.com, and sts.windows.net are all reachable on TCP 443 from the HoloLens's network segment. If your org uses Conditional Access policies, check the Entra sign-in logs for this user's device, a Conditional Access block will loop you back to the login screen with no error message in the app.
The video in Dynamics 365 Remote Assist looks blurry and pixelated. How do I get 1080p quality?
HD 1080p at 30fps requires a minimum of 1.5 Mbps up/down, but the optimal experience needs 4–5 Mbps sustained in both directions. Run a speed test from the HoloLens's current network location and verify you're hitting those numbers. Also note that first-generation HoloLens hardware may not achieve full 1080p quality even at 4–5 Mbps, this is a hardware limitation documented by Microsoft. If you're on first-gen hardware and quality is critical, consider upgrading to HoloLens 2. Beyond bandwidth, jitter above 30ms will cause video artifacts even when raw throughput is sufficient, use Teams CQD to check jitter specifically.
Can I use Dynamics 365 Remote Assist without a HoloLens, like from a phone or PC?
The expert on the other end of the call uses the standard Microsoft Teams desktop or mobile app, no HoloLens required on that side. More recently, Microsoft added Remote Assist functionality to Teams Mobile, giving field workers an alternative to HoloLens for certain use cases. However, the full mixed reality experience with spatial annotations and the shared HoloLens field-of-view is only available when the frontline worker is using a HoloLens device. Check the Microsoft Teams Mobile documentation for details on what capabilities are available in that mode.
How do I share OneDrive files and snapshots during a Remote Assist call?
During an active Remote Assist call on HoloLens, you can send snapshots of your current view to the remote expert, and the expert can share files back to you from OneDrive. For this to work, the SharePoint and OneDrive endpoint *.sharepoint.com must be accessible on TCP 443 from the HoloLens's network. Snapshots can also be saved directly to OneDrive from the session. If file sharing isn't working, check your firewall logs for blocked requests to the *.sharepoint.com wildcard, corporate DLP proxies frequently interfere with this endpoint.
What should I do now that Dynamics 365 Remote Assist is reaching end of support in December 2026?
Microsoft has announced that both Dynamics 365 Guides and Dynamics 365 Remote Assist will no longer be available after December 31, 2026. If your organization relies on Remote Assist for field service operations, start planning your migration now, don't wait until Q4 2026. Microsoft is directing customers toward Remote Assist capabilities in Microsoft Teams Mobile as the forward path. Evaluate whether the Teams Mobile workflow meets your operational requirements, identify any gaps in spatial annotation or HoloLens-specific features, and begin piloting with a small group of technicians so you have time to adapt before the hard cutoff date.