Connectivity Troubleshooting · Clash Technical Blog

How Do You Fix the Core Exiting After Windows Sleep in FlClash?

FlClash 0.8.97 may exit Core after an IPC timeout under Windows Modern Standby; v0.8.98 fixes this and Geo information not refreshing. Retest with the original configuration and roll back the entire installation if problems occur.

  • FlClash
  • v0.8.98
  • Windows
  • Modern Standby
  • Geo resources
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After the computer wakes, the window may remain even though the process handling connections has stopped. Use the pre-sleep configuration and website to check both process status and new requests. File sizes and times on the resources page are a separate check, not proof that networking works.

Sleep-Related Core Exit and Geo Display Fixes in v0.8.98

Choose the v0.8.98 checks that match your symptoms. The FlClash fixes released on 2026-9-14 cover Core—the core that handles proxy traffic—exiting during Windows sleep, and Geo file sizes and times failing to refresh after updates finish.

Choose what to check based on the symptoms

SymptomDoes It Match This Fix?Next step
It works before Windows sleeps; after wake, the FlClash window remains but the Core has stoppedPossible matchConfirm Modern Standby, then upgrade and compare under the same conditions
The Geo update reports completion, but the resource page still shows the old size and timeMatches the second UI issueAfter upgrading, wait for the update state to end, then check the file details
The entire computer has no network connection after wakeInsufficient evidenceCheck Wi-Fi, the network adapter, the system proxy, and TUN first
The Geo file download fails or rules cannot loadNot covered by the second fixCheck the download, checksum, path, and Core logs
Connection problems after sleep on Android or macOSNot part of the documented Windows pathTroubleshoot the platform's VPN, permissions, and background restrictions

Confirm Modern Standby and Save Pre-Upgrade Records

Use the Modern Standby checks in this section only if Core stops after Windows wakes from sleep. If only Geo file details fail to refresh, save your configuration and the resource page’s size and time readings, then continue with official installation and the later Geo checks.

The FlClash fix commit specifically targets Windows Modern Standby. Microsoft documents powercfg /a as the way to view the sleep states supported by a computer.

If the output includes Standby (S0 Low Power Idle), the device uses this standby model. It may appear as Network Connected or Network Disconnected.

During Modern Standby, the desktop app may be suspended while child processes of the service or Helper remain in a different state. If the app stops reading while Helper still holds Core, IPC (communication between processes) may time out after writing only part of the data. This is the partial-frame write timeout.

If powercfg /a shows only traditional S3, or the computer was merely locked or had its display turned off without entering sleep, this causal chain does not directly apply. You can still upgrade to the stable release, but troubleshooting should continue with network-adapter recovery, the system proxy, TUN, DNS, and the node.

Check Available Sleep States in Windows Terminal
powercfg /a

The output includes Standby (S0 Low Power Idle)

The scope matches. Continue comparing v0.8.97 and v0.8.98 with the same workflow.

Only Standby (S3) is available

Do not attribute the problem to this Modern Standby fix. Continue troubleshooting the general sleep-recovery path.

The system reports no available sleep states

Address the Windows or device power configuration first. Do not substitute a FlClash upgrade for a system-level fix.

The Core stops even when the screen is only locked

Preserve the logs and reproduction conditions, and check app exit behavior, the Helper, and security software. Do not treat a screen lock as a confirmed sleep timeout.

The first fix addresses the IPC lifecycle among the FlClash desktop app, the Helper child process, and the Core. The old logic closed the IPC connection when a partial-frame write timed out, so the read loop then stopped the Core. The new logic keeps waiting through timeouts and closes the connection only on a hard error.

Use the in-app export or backup feature and save the copy outside the app data directory. Remove the subscription URL, node passwords, and personal paths before sharing logs.

Do not refresh the subscription, switch nodes, or change DNS yet. Record the current FlClash version, Windows version, installer architecture, Profile, policy group, fixed node, and whether you use the system proxy or TUN. Complete a real HTTPS request to one target and confirm that it appears in Connections.

To validate the sleep issue, first use Task Manager or the FlClash status page to record that the Core is running, then put the computer into normal sleep and wake it. Keep the comparison minimal: the same Profile, node, network, and traffic-capture mode.

Record the Geo file to update, its current size, and displayed time on the resources page so you can compare the interface before and after updating. Do not delete files to create a change or use subscriptions, nodes, or rulesets as test files.

FlClash Process Relationships During Windows Modern Standby
  1. FlClash desktop appMay be suspended when Windows enters low-power standby
  2. Helper child processContinues to host the Core and exchanges state with the app over IPC
  3. Partial-frame write stallsThe old logic treats the timeout as a disconnect and stops the Core
  4. v0.8.98 resumes the writeKeeps waiting after a timeout and closes the connection only on a hard error

This fix applies only to the IPC path where the app is suspended during Modern Standby while the Helper continues running. Other sleep-related failures involving the network adapter, node, DNS, or TUN still require separate troubleshooting.

Install v0.8.98 from the Official Release

This fix is included in the official v0.8.98 Release, so you do not need a main-branch build. Most Windows computers with Intel or AMD processors should use windows-amd64-setup.exe; Windows on ARM devices should use windows-arm64-setup.exe.

The portable ZIP is only suitable for users who already use a portable directory and can manage the data location.

As of 9/17/2026, this site has verified and provides v0.8.98 backups, while retaining older files. To obtain these fixes, choose a v0.8.98 backup identified on the download page, or the matching asset from the official chen08209/FlClash Release, and compare the file hash with SHA256SUMS from the same Release.

Before installing, disable the system proxy or TUN, confirm that the device can connect directly, and fully exit from the FlClash menu. Keep the original configuration directory and pre-upgrade backup, and replace only the complete app. Do not copy a new Helper, Core, DLL, or resource file individually into the old installation directory.

Verify the Windows Installer SHA256
Get-FileHash .\FlClash-0.8.98-windows-amd64-setup.exe -Algorithm SHA256

Upgrade Only the App in One Pass

  1. Confirm the Official Tag

    Open the v0.8.98 Release from chen08209/FlClash and confirm that it is not a prerelease page or a third-party repack.

  2. Choose the Correct Architecture

    Choose amd64 for a typical x64 computer and arm64 for Windows on ARM. Do not share a data directory between the installer and portable ZIP editions.

  3. Verify Integrity

    Run Get-FileHash on the installer and compare the complete SHA256 with SHA256SUMS from the same Release.

  4. Install After Fully Exiting

    Restore direct connectivity and exit the old app first, then install the complete v0.8.98 package over it. Do not change the Profile, DNS, or node at the same time.

As of 9/15/2026, v0.8.98 is the latest official stable FlClash release. It confirms only two included commits: 60f371a handles partial IPC frame-write timeouts during Windows Modern Standby, and c5bf5bd refreshes file details after the Geo update state ends.

Validate Both the Core and a Real Request After Wake

After starting v0.8.98, first confirm that the version, Profile, policy selection, and previous traffic-capture mode are still correct. Complete one pre-sleep HTTPS request and confirm its record in Connections, then enter standby through the Windows sleep control. Do not change settings immediately after wake.

First check whether FlClash can still read the Core state, then access the same HTTPS target and look for a new entry in Connections. An open window does not prove that the Core is alive, and a displayed node-latency value does not prove that system traffic has recovered. The state, connection record, and real request must all succeed.

Repeat the same sleep-and-wake cycle at least twice so one fast network recovery is not mistaken for a fix. Use the same network, Profile, node, and mode each time. If the first cycle succeeds and the second fails, save the first app error and first Core error before moving to the other troubleshooting paths below.

After the Geo file update finishes, check file size and modification time

The second fix corrects UI state. The old version read the Geo file as soon as the update request returned, when the Core might not have finished writing it, so the resource page could keep showing the old size and time. The new version waits until the update state actually ends before rereading. This does not mean the old version necessarily failed to update the file, and it is not a GeoIP or GeoSite data-content update.

On the v0.8.98 resource page, select the Geo item recorded before the upgrade and update it through the normal in-app control. Do not click repeatedly as soon as the update request returns, and do not overwrite the resource in a file manager. Wait until the item's updating state actually ends.

The new implementation rereads the file details when the update state changes from in progress to finished. If the official source actually returns a different file, the displayed size or time should refresh. If the remote content is unchanged, an identical size alone does not show that the fix failed.

This validation only proves that the UI rereads file properties at the correct time. Rule-matching problems, Geo download failures, checksum failures, or a Core that refuses to load the file must be investigated separately from the first error; repeatedly refreshing the page will not solve them.

If the resource content changed, reload the configuration and check one related rule match to distinguish the UI display from the Core's actual use.

Where to Check When Core Runs but Connectivity Fails

If Core is still running after wake in v0.8.98 but the system cannot access the internet, investigate other causes rather than focusing only on this IPC fix. Disable FlClash’s traffic handling and confirm direct access, then check whether Wi-Fi or the wired adapter recovered, the system proxy still points to the current port, TUN and Helper have permission, and DNS and the node work.

If the Core still stops, save the FlClash version, powercfg /a output, traffic-capture mode, first app error, and first Core error from before and after sleep. Do not reinstall the Helper, change the Profile, modify DNS, and switch nodes all at once, or you will not be able to tell whether v0.8.98 still has an uncovered IPC path.

The Core is alive, but Wi-Fi or the wired adapter did not recover

Exit FlClash and restore the system network first without changing the proxy configuration.

Direct connectivity works, but system-proxy mode fails

Verify that the Windows proxy points to the current FlClash port and that no other proxy program overrides it.

The system proxy works, but only TUN fails

Check the Helper, permissions, DNS, and virtual adapter, and temporarily return to the system proxy.

Connections has a record, but the request times out

Pin another known-working node to separate a node failure from local recovery.

v0.8.98 still stops the Core consistently

Preserve the minimal version comparison and redacted logs, then report the problem in an official FlClash issue.

Roll Back the Complete App if the Upgrade Fails

If v0.8.98 cannot start, read the Profile, or preserve the previous proxy path on this computer, disable the system proxy and TUN, confirm that direct connectivity returns, and fully exit the app. After saving redacted logs and a copy of the current data, reinstall the complete official version that was verified to work before the upgrade.

You can roll back to a personally verified v0.8.97 or earlier stable version, but doing so removes the Windows sleep Core-survival and Geo detail-refresh fixes from this release. Do not insert only an old Helper, Core, or DLL into v0.8.98, and do not overwrite the official installation directory with a third-party portable package.

After restoring, import the pre-upgrade backup and repeat startup, HTTPS, sleep, and exit recovery with the same Profile, node, network, and traffic-capture mode. A consistently working old version and consistently failing v0.8.98 provide a comparison strong enough for further reporting.

Upgrade or rollback completion criteria

  • The running version, installer source, architecture, and SHA256 can be verified
  • The Profile, overrides, policy groups, and node selection match the backup
  • A real HTTPS request succeeds through the system proxy or TUN and has a Connections record
  • The Core state and request results before and after Windows sleep are recorded
  • File details are reread after the Geo update state ends
  • After exiting FlClash, system traffic capture is removed and the device returns to direct connectivity
  • App, Helper, Core, and DLL files from different versions were not mixed
  • Logs, screenshots, and reports contain no subscription URL, node passwords, or personal paths

If new v0.8.98 issues appear later, continue distinguishing a report, maintainer confirmation, a fix commit, and an official Release. One user report cannot be generalized into a platform-wide failure, and a commit on the main branch cannot replace a signed stable package.

References