When the Slack desktop app says the update failed, restarts over and over or sits on "Updating Slack", the problem is almost always a blocked or damaged local copy of the app, not your workspace. Quit Slack completely, make sure it can write to its own folder, and reinstall it from Slack's download page. Your messages are stored on Slack's servers, so a reinstall does not delete them.
Key takeaways
- An update loop is a local app problem. Your channels, files and messages live in the cloud and are not affected.
- On Windows, the usual blockers are a leftover Slack process, a security tool or a damaged install folder.
- On Mac, a frequent cause is running Slack from the Downloads folder or the mounted disk image instead of Applications.
- Slack in a browser is a safe way to keep working while you repair the desktop app.
- This page covers the update loop only. For general crashes, slow loading and notifications, use the broader guide linked below.
What the update loop looks like
People describe a handful of patterns. Slack starts, shows an update message, closes and reopens, then repeats. Or it shows a banner saying an update is ready, but clicking Restart does nothing. Or it reports that it could not update and asks you to download it again. On Windows these usually leave an app that never reaches your workspace. On Mac you may see a message that an update could not be installed, or Slack may quit without any message.
If Slack opens but loads slowly, drops messages or fails to send, that is a different problem, and our Slack not working fix covers it. The rest of this page is about updating only.
Why Slack fails to update
| Cause | How to recognise it | Fix section |
|---|---|---|
| Slack still running in the background | Update starts but never finishes; Slack icon stays in tray or menu bar | Step 1 |
| App cannot write to its folder | Mac: app runs from Downloads or a disk image; Windows: locked or restricted folder | Step 2 |
| Blocked by security software or proxy | Updates fail only on work or filtered networks | Step 3 |
| Damaged local data | Loop persists after restart and update check | Step 4 |
| Corrupt install | Reinstall needed; other fixes do nothing | Step 5 |
| Not enough disk space or wrong clock | Downloads stall or fail with certificate messages | Step 6 |
Step 0: Keep working in the browser
While you repair the app, sign in to your workspace in a browser from the Slack website. You can send messages, join calls where your plan allows and read files, so the loop does not have to stop your day. This also proves that your account and workspace are fine, which narrows the problem to the desktop install.
Step 1: Quit every Slack process
A hidden Slack process can lock files the updater needs to replace.
Windows: right-click the taskbar, open Task Manager, find every Slack entry on the Processes tab and choose End task. Or run this in Command Prompt:
taskkill /f /im slack.exeAlso look for Update.exe in Task Manager and end it too, because Slack's updater runs under that name. Slack's own help page for updating the desktop app tells you to check for both Slack.exe and Update.exe.
Mac: press Cmd+Option+Esc, select Slack, and choose Force Quit. Also look in the menu bar for the Slack icon and quit it from there.
Wait ten seconds, then start Slack again. If it was just a stuck helper process, the update now finishes by itself.
Step 2: Fix where the app is installed
On Mac: drag Slack into the Applications folder and open it from there. Running Slack from Downloads or a mounted disk image can stop it from updating itself, because macOS may run it from a restricted location. Eject the disk image, move the app to Applications, and start it again. Also confirm that you are logged in as an administrator or can enter an administrator password when asked, because updating an app in Applications may require it. If you installed Slack from the Mac App Store, updates come from the App Store instead, so open the App Store, check the Updates section and install the Slack update there.
On Windows: the classic Slack installer places the app in your user profile, not in Program Files, so you do not need administrator rights for a normal update. Problems appear when that folder is locked by another program or by file permissions. If you installed Slack from the Microsoft Store, the Store handles updates: open the Store, go to Library, and check Slack. Mixing the Store version with the standalone version on one PC can cause confusing results, so keep only one.
Step 3: Rule out a firewall, proxy or filter
The updater downloads files from Slack's servers. A work firewall, school filter, VPN or antivirus web shield can block that download without breaking normal browsing. Test by switching to another network, such as a phone hotspot. If the update completes there, ask your IT administrator to allow Slack's update traffic, or turn off the filtering feature of your security product for a test and then update it to a version that works. Keep this test short and turn protection back on right after.
Also open Settings, then Network and Internet, Proxy on Windows and make sure no old proxy address is set that you no longer use. On Mac, check System Settings, Network, Details, Proxies for the same thing.
Step 4: Clear Slack's local data
Damaged cache files can make the app restart before it ever finishes the update. Clearing them only removes data stored on your computer. You will have to sign in again, and Slack redownloads your history.
Windows: quit Slack, press Win+R, type %APPDATA%\Slack, and rename that folder to Slack.old. Start Slack and sign in.
Mac: quit Slack, open Finder, choose Go, Go to Folder and enter ~/Library/Application Support/Slack. Move the Slack folder to the Desktop as a backup, then start Slack and sign in. Delete the backup only after everything works. This folder applies to the direct-download version. For the Mac App Store version, use the Mac App Store steps on Slack's Update the Slack desktop app help page, because its data is kept elsewhere.
Microsoft Store version on Windows: its data does not live in %APPDATA%\Slack. Slack's help page lists it under C:\Users\<name>\AppData\Local\Packages\91750D7E.Slack_8she8kybcnzg4\LocalCache\Roaming. Check there instead, so you do not rename the wrong folder, and rename rather than delete.
If you are signed in to several workspaces, you will need to add them again. Have your sign-in method ready, especially if you use single sign-on.
Not sure what is wrong? Get a diagnosis first.
Our certified tech can connect remotely, check your software, drivers and backups, and tell you honestly whether the problem needs a hands-on repair.
Step 5: Reinstall Slack cleanly
When nothing else works, a clean install replaces every file at once.
- Windows: open Settings, Apps, Installed apps, find Slack, choose Uninstall. Restart the PC. Download the current installer from Slack's official download page and run it as your normal user.
- Mac: quit Slack, drag it from Applications to the Trash, empty the Trash, then download the current installer from Slack's official page and drag the new copy into Applications.
- Start Slack, sign in, and confirm the version. On Windows, open the menu (the three-line icon), then Help, then About Slack. On Mac, open the Slack menu, then About Slack. Check for updates there if the menu offers it.
Install only from Slack's own site or the official store for your system. Third-party download sites sometimes bundle extras and can themselves cause update trouble.
Step 6: Disk space and the system clock
Updates need free space to unpack. If your drive is nearly full, free some room and try again. A wrong date or time can also break secure downloads, so turn on automatic time. On Windows, open Settings, Time and language, Date and time. On Mac, open System Settings, General, Date and Time. On Windows machines that fail to update many apps, our guide to stuck Windows updates may explain why. The same type of loop on another chat app is explained in our Discord update failed guide, which makes a useful comparison if both are affected.
What not to do
- Do not keep clicking Restart to update more than a couple of times. Repeated forced restarts can leave half-written files.
- Do not copy Slack files from another PC. Version and signature mismatches create a new problem.
- Do not download Slack from a search ad or a mirror site. Use the vendor's page.
- Do not delete your whole user profile or Library folder. You only need the Slack folders named above.
When to ask for help
Ask for help if the loop returns after a clean install on more than one network, if you manage Slack on many company PCs and the same update fails on all of them, or if security software keeps removing parts of the app. For a business with a policy, proxy or software-deployment setup, the cause may be in how updates are allowed. Our team can look at the computer in a remote session: see remote computer repair and the Windows support page.
Preventing update loops
- Install Slack into Applications on Mac and keep one version type on Windows, either standalone or Store.
- Restart the app when it asks for an update, instead of leaving the pending update for weeks.
- Keep at least a few gigabytes free on your system drive.
- If your company filters traffic, ask for Slack's update endpoints to be allowed, rather than relying on the browser alone.
- Keep the browser version of Slack bookmarked as a backup.
FAQ
Why does Slack keep saying update failed?
The updater cannot replace the app's files. The usual reasons are a hidden Slack process, a security tool blocking the download, or an app running from a folder where it cannot update itself.
Will I lose messages if I reinstall Slack?
No. Messages, files and channels are stored on Slack's servers. Reinstalling removes only the local copy and local settings.
Why does Slack restart again and again on Mac?
If the app runs from Downloads or a disk image, it can fail to install its update and start over. Move it to Applications and reopen it.
Can I use Slack while the app is broken?
Yes. Sign in to your workspace in a web browser. It handles messages and files while you repair the desktop app.
Does the Microsoft Store version update differently?
Yes. The Store manages that version, so check updates in the Store's Library. Do not install the standalone version on top of it.
Is this the same as Slack not working?
No. Slack not working covers crashes, slow loading and notifications. This page is only about updates that fail or loop.
Does a VPN cause the update to fail?
It can. Some VPN and filter products block the update download. Test on another network to see.