How to Resolve the XULRunner Platform Version Is Not Compatible Error

How to Resolve the XULRunner Platform Version Is Not Compatible Error

Here we can see, “How to Resolve the XULRunner Platform Version Is Not Compatible Error”

If you use Mozilla Firefox, you may see a Xulrunner Error when trying to open the browser. This issue will prevent you from using the Firefox browser. This issue can also occur when starting Mozilla ThunderBird. Most users had this difficulty with both apps.

Why does the Xulrunner Error occur?

Incomplete Update: This error is caused by an incomplete Firefox installation/update. A faulty internet connection, an abrupt system shutdown, or an antivirus can stop Firefox from updating. Your Firefox update doesn’t fully install when this happens, leaving you with a mix of old and new data in the Firefox program folder.

See Also:  How to Fix: Microsoft Edge Update Installation Error STATUS_INVALID_IMAGE_HASH on Windows 10?

Step 1: Reinstall Firefox

Because an incomplete update installation causes the issue, a clean install is usually the remedy. This includes uninstalling the program and deleting its data completely, so nothing remains on the system to obstruct the new installation. Installing a new copy of the application usually solves the issue. So, follow the steps below to install Firefox fresh.

  1. Hold Windows and R.
  2. Enter appwiz.cpl.
  3. Find and select Firefox.
  4. Click Uninstall and follow the prompts. When the uninstaller asks if you want to erase personal files, don’t do it. Don’t delete your files like your Firefox profile or bookmarks.
  5. Uninstall the software. Hold Windows and E.
  6. Enter C:\Program Files\ in the address bar.
  7. Delete the Firefox folder.
  8. Enter C:\Program Files (x86)\ in the address bar.
  9. Delete the Firefox folder.
  10. Reboot.
  11. After rebooting, click here to get a new version of Firefox.
  12. Install the newest Firefox version by running the downloaded file.

User Questions:

How do I fix a Firefox error?

  1. Abort FF processes. 1.1 Ubuntu 1.2 Close the Firefox process in Windows Task Manager.
  2. Eraser the profile lock file
  3. Remove -no-remote-startup.
  4. Set up a file share connection.
  5. Verify permissions.
  6. Unlock a profile’s info.

How to activate right-click in Firefox

You can adjust a setting in Firefox to always have access to the right-click context menu. (1) Type or paste about:config into a new tab and hit Enter/Return. Click the button pledging caution.


What is XULRunner?

XULRunner is a runtime that can boot several XUL + XPCOM apps like Firefox and Thunderbird. XULRunner saves configuration info (bookmarks, cookies, contacts, etc.)

Is it a virus?

xulrunner.exe is a valid process file, and by default, it’s in C:Program Files. Malware writers create viral files containing dangerous scripts and save them as xulrunner.exe to disseminate them online.


Close and reopen Firefox. If Firefox is unresponsive, force it to close. Click Force Quit in the Apple menu, select Firefox, and then press “Option,” “Command,” and “Esc (Escape).” Reopen Firefox and test your issue.