Black screen after sign-in on virtual desktop hosts
After the August 2026 preview and subsequent updates, some users saw a black screen after sign-in with the desktop session failing to load; Explorer crashes appear in application event logs.
Does this match your environment?
- Windows scope
- 24H2 / 25H2
- Architecture
- Unknown — not universal
- App / driver
- Azure Virtual Desktop / FSLogix
- Conditions
- Primarily Azure Virtual Desktop hosts using FSLogix; more frequent with some existing user profiles.
A matching version is only a starting point. This page does not diagnose an individual device.
Evidence & current resolution
Microsoft lists this scope as resolved on 2026-10-13. Resolving update: KB5127648.
- Evidence ID
- official-black-screen-avd
- Source groups
- 1 · official publication
- Evidence basis
- Manually reviewed public source; no independent device test
Suggest a correction
Recorded timeline
Originating update released
KB5120998Official resolution recorded
KB5127648
Snapshot reviewed
Added to this curated collection. Earlier acknowledgement time was not independently captured.
Could this be what you are seeing?
Checked 2026-10-25The official symptom list for this issue, so you can compare it with what your hosts report before reading further.
Affected users might see a black screen after signing in, with the desktop session failing to load automatically.
In some cases, users might be unable to access their desktop until the desktop session is started manually.
Application event logs on the host might show Windows Explorer crashes.
The official text ties the issue to installing KB5120998 (released 2026-08-27) and subsequent updates.
This list mirrors the official symptoms only. It cannot diagnose an individual device, and an absent symptom does not rule the issue out.
Evidence: tracked:lib/catalog.ts#issues.black-screen-avd · tracked:docs/qa/evidence/ingest-state-2026-10-24.json#kb5124008 · tracked:docs/qa/evidence/review-2026-10-25.md#black-screen-avd
Which environments the official scope covers
Checked 2026-10-25What the captured official sources state about who is affected. Nothing here is widened beyond the official wording.
- Windows versions
- Windows 11 24H2 and 25H2
- Introduced by
- KB5120998 (August 2026 optional preview, released 2026-08-27) and subsequent updates
- Primary observation environment
- Primarily observed on Azure Virtual Desktop (AVD) hosts using FSLogix
- Reported frequency
- The issue appears to occur more frequently with some existing user profiles
"Primarily observed" is the official wording, not a boundary. Environments outside the primary observation group are neither confirmed nor excluded here — see What is not yet known below.
Evidence: tracked:lib/catalog.ts#issues.black-screen-avd · tracked:docs/qa/evidence/ingest-state-2026-10-24.json#kb5124008 · tracked:docs/qa/evidence/review-2026-10-25.md#black-screen-avd · tracked:docs/qa/evidence/candidates-20261024172211.json
Official status and fix
Checked 2026-10-26The resolution path Microsoft published for this issue, and the workarounds it published for devices not yet on the fix. The workarounds below are a transcription of the official text, not this site's own steps.
- Status
- Resolved. Microsoft recorded resolution on 2026-10-13.
- Official fix
- Install Windows updates released on and after October 13, 2026, such as KB5127648 (October 2026 security update).
- Microsoft recommendation
- Install the latest Windows update for the device, as it contains further improvements and issue resolutions.
- Workaround applicability (official)
- If you install an update released October 13, 2026 (KB5127648), or later, you do not need to use a workaround for this issue. If you are using an update released before October 13, and have this issue, you have the option to apply the following workaround. Affected customers can apply one of the following workarounds to mitigate the issue.
Transcribed from Microsoft's release-health entry for this issue: "Users can temporarily mitigate this issue by opening Task Manager (Ctrl+Shift+Esc), selecting Run new task, entering explorer.exe, and selecting OK."
Transcribed from the same entry: "This issue is mitigated using Known Issue Rollback (KIR). For enterprise-managed devices where Windows updates are managed by IT departments, IT administrators can apply the KIR by installing and configuring the Group policy listed below. The special Group Policy can be found in Computer Configuration > Administrative Templates > <Group Policy name listed below>. Group Policy downloads with Group Policy name: Download for Windows 11, version 26H1: KB5124006 260924_20071 Known Issue Rollback. Download for Windows 11, version 26H2, Windows 11, version 25H2 and Windows 11, version 24H2: KB5124010 260924_20021 Known Issue Rollback. Important: You will need to install and configure the Group Policy for your version of Windows to resolve this issue. You will also need to restart your device(s) to apply the group policy setting. Note that this Group Policy will disable the change causing this issue until a resolution is released in a future Windows update. For information on deploying and configuring this special Group Policy, please see How to use Group Policy to deploy a Known Issue Rollback."
Both workarounds were published on the Windows 11 25H2 release-health status page after this site's captured sources were taken; they are transcribed from that page as fetched on 2026-10-26, and the operational wording is kept as published, including the official Important note. This site adds no steps of its own beyond the transcription. The resolution guidance is unchanged: install KB5127648 (released 2026-10-13) or a later update.
Evidence: tracked:lib/catalog.ts#issues.black-screen-avd · tracked:docs/qa/evidence/ingest-state-2026-10-24.json#kb5124008 · tracked:docs/qa/evidence/review-2026-10-25.md#black-screen-avd · live:learn.microsoft.com/en-us/windows/release-health/status-windows-11-25H2 fetched=2026-10-26 sha256=9d0278b76ba833b0b12ae2912f118a2534f8b9edb1edcf3b1a55e728f0a16671
What is not yet known
Checked 2026-10-25Questions the captured official sources do not answer. Each stays open until an official source addresses it.
Whether FSLogix deployments that are not AVD hosts are affected is not stated. The official text says the issue was primarily observed on AVD hosts; it does not confirm or exclude other FSLogix environments.
Whether virtual desktop platforms other than Azure Virtual Desktop are affected is not stated.
Microsoft says the issue appears more frequently with some existing user profiles, but does not specify which profile configurations.
Evidence: tracked:lib/catalog.ts#issues.black-screen-avd · tracked:docs/qa/evidence/ingest-state-2026-10-24.json#kb5124008 · tracked:docs/qa/evidence/review-2026-10-25.md#black-screen-avd
What to do next
Checked 2026-10-26The actions this evidence supports. Nothing here goes beyond the official fix.
Install the latest Windows update for the device. Any update released on or after October 13, 2026, such as KB5127648, contains the official fix.
Confirm the hosts have installed an update released on or after October 13, 2026 before investigating further; Microsoft lists the issue as resolved in those updates.
Both official workarounds are transcribed in the status and fix section above; this site adds no steps of its own. If the device already runs an update released October 13, 2026, or later, Microsoft states no workaround is needed.
Evidence: tracked:lib/catalog.ts#issues.black-screen-avd · tracked:docs/qa/evidence/ingest-state-2026-10-24.json#kb5124008 · tracked:docs/qa/evidence/review-2026-10-25.md#black-screen-avd