FIX: Couldn’t be saved because source file couldn’t be read

Matthew Adams
by Matthew Adams
Windows & Software Expert
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  • Mozilla Firefox is a browser or choice for many users, but even great browsers such as Firefox have their share of issues.
  • Users reported Could not be saved because the source file could not be read error in Firefox, and in today’s article we’ll show you how to fix it.
  • Firefox is a great browser, but if you have any more issues, be sure to check our Firefox errors Hub for more guides like this one.
  • Do you want to learn more about Firefox? If so, you might want useful information in our Firefox Hub so be sure to visit it.
Could not be saved because the source file could not be read firefox

The Firefox browser has a few download error messages. One of those error messages states: <filename> could not be saved, because the source file could not be read. Try again later, or contact the server administrator. When that error message pops up, Firefox users can’t download and save files. Here are a few resolutions that might fix that issue.

How do I fix Could not be saved, the source file could not be read error?

1. Check your Internet connection

First, check your internet connection hasn’t gone down. The server might have been interrupted when downloading. As such, open a few website pages in your browser.

If they don’t open, then a lost connection is the issue. This article provides further details for fixing net connections.

2. Delete the compreg.dat file

  1. The compreg.dat file in your Firefox profile folder might be corrupted. To delete a corrupted compreg.dat file, open Firefox and enter about:support to open the tab shown directly below.

  2. Press the Open Folder or Show Folder button shown in the snapshot directly below. That will open your Firefox profile folder in File Explorer.
  3. Close the Firefox browser.
  4. Right-click compreg.dat and select Delete to erase that file.

3. Adjust the network.http.accept-encoding Preference Value

  1. If you’re getting the could not be saved error when downloading PDFs, adjusting the network.http.accept-encoding preference might resolve the issue. You can adjust that preference by entering about:config in Firefox‘s URL bar.
  2. Scroll to the network.http.accept-encoding setting on the about:config tab shown directly below.

  3. Double-click the network.http.accept-encoding preference to open its Enter string value window as in the snapshot below.
  4. Erase all the value text in the text box, and press the OK button.

4. Disable download manager extensions

  1. Click the Open menu button at the top right of Firefox‘s window.
  2. Click Add-ons to open the tab shown directly below.

  3. Click Extensions to open a list of extensions.
  4. Press the Disable buttons beside download manager extensions. Alternatively, press the Remove buttons instead.

5. Adjust the attributes setting for places.sqlite

  1. Input about:support in Firefox‘s address bar, and press the Enter key.
  2. Press the Open Folder button to open your profiles folder in File Explorer.
  3. Right-click places.sqlite and select Properties from the context menu.
  4. Uncheck the Read-only check box if it’s selected.
  5. Click Apply and OK to close the window.

6. Reset the Firefox browser

  1. To refresh Firefox, input about:support in the browser‘s URL bar and press Enter to open the troubleshooting tab.

  2. Click the Refresh Firefox button on that tab.
  3. Then select the Refresh Firefox option on the dialog window to further confirm.

7. Reinstall the Firefox Browser

  1. Reinstalling the Firefox browser might also fix the could not be saved issue as that will replace corrupted software files. To reinstall Firefox, open Run by pressing the Win key + R hotkey.
  2. Enter appwiz.cpl in the Run text box, and click the OK button.
  3. Then select Firefox, and press the Uninstall button.
  4. That will open Firefox‘s uninstall wizard. Press the Next button on the wizard to remove the program.
  5. Then reinstall the same Firefox version you removed. If it isn’t Firefox 57, you can download earlier Fox versions with an alternative browser from this website page.
  6. Open Firefox‘s setup wizard to add the browser to Windows.

One of those resolutions will probably fix Firefox so that you can download software and documents with the browser once more. Clearing your download history, selecting an alternative download folder and switching anti-virus software off might also help resolve the issue.

If you have further suggestions for fixing this Firefox issue, please share them below.

FAQ: Learn more about Firefox

  • How do I reinstall Firefox?

Reinstalling Firefox is easy, you just need to remove it from the Settings app and then download and install the latest version.

  • Does Firefox have virus protection?

Firefox can recognize certain malicious websites, but for full protection, it’s advised to use a dedicated antivirus.

  • How do I change my download settings in Firefox?

To change the download settings in Firefox, click on the Menu icon and choose Options. Locate Files and Applications section and change your settings from there.

  • How do I fix failed download in Firefox?

To fix downloads in Firefox, check your antivirus settings. If that doesn’t help, you might have to reinstall Firefox.

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