Fix: ‘Data Text HTML 3CBody 3E 3C 2Fbody 3E’ on Steam

Certain Steam users are reporting that every time they open up the program they end up seeing a blank page with the [data:text/html,%3Cbody%3E%3C%2Fbody%3E] error. Upon closing this window, the main Steam interface starts normally, but the error will return the next time Steam is started.

Steam Error [data:text/html,%3Cbody%3E%3C%2Fbody%3E]
After investigating this particular issue, it turns out that there are several different underlying causes that might be causing this Steam error. Here’s a shortlist of scenarios that you might be dealing with:

  • Outdated Steam client – One of the most common culprits that will cause this issue is an outdated Steam installation. Keep in mind that Valve has patched this particular issue with a couple of hotfixes. You can take advantage of them by forcing your Steam client to update to the latest available build.
  • Steam account is not part of Beta Program – If updating to the latest public build has not made a difference in your case, another thing you can try is to sign up for the Beta Program to get the absolute hotfixes that are not yet available for regular Steam users.
  • Corrupted Steam cookie or cache – As it turns out, temporary cache and cookie data accumulated by the built-in Steam browser can also be responsible for this issue. To fix the issue in this particular case, you’ll need to clear both the cookies & the cache from your Steam settings.
  • Firewall interference – Depending on which Steam version you’re using (modified or not) and your firewall, you can expect an interference that prevents Steam from communicating with the main server. To avoid these sorts of issues, you should establish a whitelisting rule for the main Steam executable and used ports.

Now that we went over every potential scenario that might be responsible for the apparition of this issue, let’s take a look at the various fixes that affected users have successfully used to get to the bottom of this issue.

Forcing Steam to Update

Keep in mind that Valve has already addressed this particular issue via a couple of hotfixes meant at eradicating this issue. Although they haven’t been entirely successful since the issue is still occurring due to a cache issue (as you’ll see below), you should start this troubleshooting guide by forcing your Steam installation to update.

According to other affected users, this will eliminate the issue in scenarios where the problem is occurring due to a bug or when there’s an issue with your Steam installation that prevents the program from auto-updating.

Note: Keep in mind that if there’s an issue with the auto-updating function, you will need to delete everything inside the Steam installation folder (aside from Steamapps, Userdata, and Steam.exe) in order to force the app to update. 

Follow the instructions below to fix the [data:text/html,%3Cbody%3E%3C%2Fbody%3E] error by forcing your Steam installation to update:

  1. Before you do anything else, ensure that every Steam process is completely closed.
    Note: This is crucial since you won’t be able to delete the complementary Steam files otherwise.
  2. Once you’ve made sure that Steam is completely closed, open File Explorer and navigate to the following location:
    C:\Program Files (x86)\Steam 

    Note: This is the default Steam installation location. If you installed the program in a custom location, navigate there instead.

  3. As soon as you arrive in the correct location, select every file and folder inside aside from Steamapps (folder) Userdata (folder) and Steam.exe (executable) and delete everything by right-clicking on a selected item and choosing Delete from the context menu.
    Deleting Non-essential Steam files
  4. Once every file has been deleted, reboot your PC and open Steam once the next startup is complete.
  5. Because you deleted all those files at step 3, the Steam installation should detect that it’s missing some dependencies and auto-update itself to the latest version.
  6. Once the update is complete, restart Steam and check if you’re still dealing with the same [data:text/html,%3Cbody%3E%3C%2Fbody%3E] error.

If the problem is still not fixed, move down to the next potential fix below.

Clear Steam’s Cookies & Browser Cache (temporary fix)

As it turns out, the [data:text/html,%3Cbody%3E%3C%2Fbody%3E] error is oftentimes related to a cookie or browser cache issue that is affecting your current Steam installation.

Fortunately for users finding themselves in this particular scenario, the fix is simple – you’ll need to access your Steam’s Settings and clear the cookies and browser cache of your Steam installation.

There are a lot of users confirming that this operation has finally allowed them to launch Steam without the [data:text/html,%3Cbody%3E%3C%2Fbody%3E] error. Unfortunately, most of them also confirm that the fix is temporary.

Even if you follow the instructions below and it resolves the issue, expect the same error to return the next time you launch Steam after you reboot your PC.

If you’re okay with a temporary fix, go ahead and start following the step-by-step guide below:

  1. Open Steam and close the black window when the [data:text/html,%3Cbody%3E%3C%2Fbody%3E] error appears.
  2. If you are asked to sign in with your Steam account, do so and make your way to the home screen of the Steam interface.
  3. Next, click on File from the ribbon bar at the top, then click on Settings from the context menu that just appeared.
    Accessing the Settings screen
  4. From the Settings screen of Steam, select Web Browser from the context menu on the left, then move over to the right-hand side and click on Delete Web Browser cache.
  5. At the confirmation prompt, click Ok to initiate the process of deleting the Steam browser cache, then wait until the operation is complete.
    Clearing the Steam cache
  6. Once the operation is complete, click on Delete All Browser cookies from the same screen, then click Yes at the confirmation prompt to take care of the browser cookies.
  7. After you made sure to delete both the web browser cache and the browser cookie of your Steam installation, reboot the app and see if the problem is now fixed.

If the problem is still not fixed, move down to the next potential fix below.

Whitelist Steam from Firewall Settings

If the methods above were not effective in your case, you should start considering the fact that you might be dealing with a permission issue facilitated by your firewall.

If you’re running a modified version of Steam, it’s not uncommon to notice that Steam connections are blocked – this can happen with both a 3rd party firewall solution or with Windows Firewall.

Important: If you have multiple firewalls running at the same time, choose one and uninstall the other and make sure you’re not leaving behind any remnant files.

Obviously, if you’re using a 3rd party suite, the steps of establishing a whitelist rule for Steam will vary from developer to developer.

But if you’re using the default Windows Firewall, you can follow the instructions below to fix the [data:text/html,%3Cbody%3E%3C%2Fbody%3E] error by establishing a whitelisting rule for Steam:

  1. Press Windows key + R to open up a Run dialog box. Next, type ‘control firewall.cpl’ and press Enter to open up the Windows Firewall window.
    Accessing the control firewall menu

    Note: If you’re prompted by the User Account Control, click Yes to grant admin access.

  2. Once you arrive inside the main menu of the Windows Defender firewall, go over the menu on the left-hand side and click on Allow an app or feature through the Windows Defender firewall.

    Allowing an app through Windows Firewall
  3. Inside the Allowed apps menu, click on Change settings button, then click on Yes when you’re prompted by the User Account Control (UAC) prompt.
    Changing the settings of Windows Firewall
  4. Once the list of allowed programs becomes editable, scroll down to the bottom of the screen and click on Allow another app.
  5. Next, from the menu that just appeared, click on Browser and navigate to the location where the game is installed.
    Allowing another app through Windows Firewall
  6.  Next, using the Browse menu, add the main executable of steam, then check both Private and Public checkboxes before clicking Ok to save the changes.
  7. After you did this, return to the initial firewall menu (step 1) and click on Advanced System settings from the vertical menu on the left.
    Accessing the Advanced System Settings
  8. When you’re prompted by the UAC prompt, click Yes to grant yourself admin access.
  9. Once you get to the next screen, click on Inbound rules from the menu on the left before clicking on New Rule from the right-hand pane.
    Creating a new firewall rule
  10. After you do this, you should see the New Inbound Rule Wizard appears on the screen.
  11. When you see this behavior occurring, choose Port when asked to select the Rule Type before clicking Next
  12. Next, select TCP from the next prompt before choosing the Specific Local ports toggle.
  13. Paste the following ports in the box in order to prevent any TCP ports used by Steam to be blocked:
  14. Next, create the second rule by choosing UDP toggle, then choose Specific Local ports and paste the following UDP ports that you wish to prevent Steam from blocking:
  15. After the required port has been successfully added, click on Next and you should land directly in the Action Prompt menu.
  16. Inside the Action Prompt menu, click on Allow the connection and hit Next one final time.
    Enforcing the rule 
  17. Finally, click Finish to save the changes you just did, then reboot your computer and launch Steam after the next startup is complete to see if the operation is now complete.

Enable Beta Updates

If you’re still dealing with the same [data:text/html,%3Cbody%3E%3C%2Fbody%3E] error even after following the instructions below, one potential fix that you can enforce is transitioning to a Beta build for Steam.

We’ve managed to find some affected users confirming that the issue went away on its own as soon as they opted to participate in the Beta program and the steam application was updated.

Note: Skip this method entirely if you’re already a member of the Beta participation program.

Follow the instructions below to access the Account tab of Steam’s Settings and opt your Steam account into the Beta participation program in order to resolve this startup Steam error:

  1. Open Steam, sign in with your account, and close the black screen once the error pops up on the screen.
  2. Once you’re inside the home screen of Steam, click on File from the ribbon at the top, then click on Settings from the context menu that just appeared.
    Accessing the Settings screen
  3. Once you’re inside the Settings screen, click on Account from the vertical menu on the left.
  4. With the Account tab selected, move over to the right-hand pane and click on the Change button associated with Beta Participation.
    Accessing the beta participation settings in Steam
  5. Next, change the Beta Participation toggle from None to Steam Beta Update and click Ok to save the change.
    Accessing the Beta programs menu
  6. At the confirmation prompt, click on Restart Steam button and wait until the platform restarts and auto-updates itself with the beta updates.
    Restarting Steam
  7. Watch the next Steam startup carefully and see if the error code has been fixed.

If you’re still seeing the black screen coupled with the [data:text/html,%3Cbody%3E%3C%2Fbody%3E] error, move down to the final potential fix below.

Repair Install Windows Versions

In case none of the potential fixes above have been effective in your case, there’s only one potential culprit left to investigate – some kind of system file corruption that is affecting your Steam installation.

If you want to avoid going for a Windows clean install and losing all your personal data, the only other option really is to go for a repair install (in-place upgrade).

This operation will essentially replace every operating system file with a healthy equivalent ensuring that no corrupted file is causing this weird error with Steam.

Depending on which Windows version you’re using, the instructions of repair installing (in-place upgrade) will be slightly different:


Kamil Anwar

Kamil is a certified MCITP, CCNA (W), CCNA (S) and a former British Computer Society Member with over 9 years of experience Configuring, Deploying and Managing Switches, Firewalls and Domain Controllers also an old-school still active on FreeNode.