FIX: Slack got stuck while processing the uploaded file

Aleksandar Ognjanovic
by Aleksandar Ognjanovic
Troubleshooting Expert
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  • Slack is used by millions worldwide, and is viewed as one of the best collaboration software tools in the world
  • A lot of files are being distributed amongst Slack users, and sometimes there are issues trying to upload them. In this article we'll explain how to fix them.
  • This article is part of our special hub for Troubleshooting Slack problems, so make sure to bookmark it for future reference as you'll definitely get another Slack error
  • Visit our dedicated Slack section for more useful articles
slack file processing frozen

Slack, the team collaboration service, is one of the most used services in the niche. There’s a large array of available features, and it basically covers everything an organization needs.

However, a few users have had a hard time uploading files to the shared channel or via direct messages. Allegedly, the upload was stuck and Slack was processing the file without any signs of success.

Now, firstly, make sure that the file isn’t corrupted. Secondly, there’s a size limit, so uploading files over few dozens of megabytes won’t work all that well.

On the other hand, if you’ve covered those two and the issue persists, check the alternative steps we enlisted below.

How do I fix Slack if it’s stuck while processing uploaded file

  1. Check connection
  2. Clear browsing data
  3. Disable antivirus temporarily
  4. Allow Slack in Windows Firewall
  5. Reinstall the app

1: Check connection

First things first. The mere glance upon this issue is enough to concur something’s wrong with your connection. Uploading files should be an integral part of the application, both for desktop and in the browser.

We suggest trying to upload some files in the desktop app (if uploads get stuck in the web app) or the web app. If you’re still unable to upload files to Slack, some connection troubleshooting is more than welcome.

Here are some steps you should follow:

  • Update Slack.
  • Restart your PC and router.
  • Disable VPN or Proxy temporarily.
  • Update router’s firmware.
  • Use a wired connection instead of Wi-Fi.

2: Clear browsing data (for browser version)

If you’re accustomed to the web app and the problem with uploads keeps reappearing on regular basis, try clearing the browsing data. The cache and cookies tend to pile up fast.

On the long run, this can affect the performance of the browser: slow down the loading and prevent traffic on the individual pages.

It can, as well, inflict the issue at hand. Here’s how to clear browsing data on 3 most-used browsers for Windows 10:

Google Chrome and Mozilla Firefox

  1. Press Shift + Ctrl + Delete to open the “Clear browsing data” menu.
  2. Select “All time” as the time range.
  3. Focus on deleting ‘Cookies’, ‘Cached Images and Files‘, and other site data.
  4. Click on the Clear Data button.slack processing uploaded file stuck
  5. Restart the browser and log into Slack again.

Microsoft Edge

  1. Open Edge.
  2. Press Ctrl + Shift + Delete.
  3. Check all the boxes and click Clear.slack processing uploaded file stuck
  4. Restart Edge and log in to Slack again.

3: Disable antivirus temporarily

Some users in distress addressed the issue by disabling the antivirus temporarily. Namely, some antivirus solutions tend to slow down or even block Slack’s execution.

This mostly concerns the desktop application, but the web-based app can be blocked by the protective solutions, too.

Even though this mostly doesn’t apply to Windows Defender, you can try disabling the web-based protection for the time being and look for improvements. Here’s how to do it:

  1. Open Windows Defender from the notification area.
  2. Choose Virus & threat protection.slack processing uploaded file stuck
  3. Select Virus & threat protection settings.slack processing uploaded file stuck
  4. Disable Real-time protection and try running Slack again.slack processing uploaded file stuck

4: Allow Slack in Windows Firewall

In order for free team communication, which includes files sharing, Slack needs to works freely. The common limitation which affects Slack’s performance is Windows Firewall.

Namely, even though it should be allowed by default, we encourage you to check the related settings and confirm it.

Follow these instructions to allow Slack to communicate freely through Windows Firewall:

  1. In the Windows Search bar, type Firewall, and open Allow an app through Windows Firewall.
  2. Click ”Change settings”.
  3. Allow Slack to communicate freely by checking both boxes.
  4. Confirm changes and restart your PC.
  5. Start Slack and look for changes.

5: Reinstall the app

Finally, if you’re using the desktop client for Slack, reinstalling it should be a good idea. Even though it’s unlikely, the corruption of installation files can happen.

And if that’s indeed the case, the best way to fix it is to completely reinstall the app. In addition, Slack comes in various versions.

So, if you’re having a hard time with the desktop client, the UWP version from Microsoft Store might do you good.slack processing uploaded file stuck

That’s it. If you’re aware of some alternative solution, we encourage you to share it with us in the comments section below.

FAQ: Learn more about Slack

  • Why is Slack not connecting?

If Slack isn’t connecting, the most likely cause is your Internet connection. If the Internet connection is working properly, try opening the Slack test page.

  • How do I insert a Word document into Slack?

To insert Word document into Slack, simply drag and drop it to the channel to share it with others.

  • Can you upload videos to Slack?

Yes, you can upload videos to Slack, but bear in mind that file upload is limited to 1GB per file.

  • Does Slack compress images?

No, Slack doesn’t compress images, and all uploaded images are available in original size and quality.

Editor’s Note: This post was originally published in June 2018 and has been since revamped and updated in March 2020 for freshness, accuracy, and comprehensiveness.