How to fix
“Source file could not be read” error on Firefox
on Windows

I cannot download needed files from the Internet using Firefox browser. It gives me a message that source file could not be read. I tried to download and save files using other browsers, so I think the problem is related to Firefox itself. How can I fix it?

"Source file could not be read” is an error that might occur when users try to download files from the Internet and save them in a preferred location using the Mozilla Firefox browser.[ref en-1] The error message might pop-up when you download any type of the files, including music, games, documents, etc.

Instead of launching the download process, the browser returns the following error message:

“ could not be saved, because the source file could not be read. Try again later, or contact the server administrator.”

While "Source file could not be read” users encounter this on Firefox, the issue was also seen on other browsers, including Google Chrome or MS Edge. The advice in error does not seem to provide any actual solutions, as trying again later brings the same results.

One of the main sources of the problem is a lost Internet connection. Thus, if Firefox gives you this error, you have to make sure that you are connected to the Internet.[ref en-2] However, if you try again and the error still appears, try the methods below to fix “Could not be saved because the source file could not be read” Firefox error.

Before you begin with the manual solutions below, we highly recommend you try running [d1] on your computer. This software can diagnose and fix many issues that occur due to different factors, for example, corrupted Windows registry or malware damage to system files. It can also take care of privacy, clearing browser cookies and web data, consequently solving issues related to those.

Methods to solve “Could not be saved because the source file could not be read” error

Method 1. Check Internet connection

You should start solving the problem with the simplest option - checking the Internet connection. However, if you can access other websites without any problems, you should try other methods to fix the Firefox error.

Method 2. Find and delete corrupted Compreg.dat file

File corruption is one of the most popular sources of various errors. In this case, the "Source file could not be read” error is often related to corruption of the Compreg.dat file. Thus, you have to delete it:

1. Open Firefox.
2. Type in the browser’s tab about:support and hit Enter.
3. In the appeared tab find Open Folder (or Show Folder) option to open Firefox profile folder.
4. Close Firefox.
5. Right-click Compreg.dat file in the Firefox profile folder and choose Delete from the drop-down menu.

Method 3. Turn off Firefox extensions

Sometimes Firefox extensions cause huge problems. Therefore, you should check if they are not causing the “Could not be saved because the source file could not be read” error too. Disable them and try to download necessary files:

1. Open Firefox and access menu.
2. Go to Add-ons and click Extension.
3. Click Disable buttons near installed extensions.

Additionally, you can click Remove button to delete them entirely.

Method 4. Check if Attributes for Places.sqlite is not set to Read-only

If the Attributes Setting for Places.sqlite is set to Read-only, it might be the reason why you have to deal with this Firefox error. Thus, you should check and adjust these settings if needed:

1. Open Firefox.
2. Enter about:support to the address bar and click Enter.
3. Click Open Folder button to open Firefox Profiles folder in the File Explorer.
4. In the appeared folder find places.sqlite, right-click it and choose Properties from the menu.
5. The places.sqlite Properties window appears. Remove the check-box from the Read-only option in the Attributes section.
   

   

6. Click Apply and then OK to save the changes.

Method 5. Reset/Refresh the browser

If none of the methods helped to get rid of the "Source file could not be read" error, you have to reset the browser. Actually, Firefox has a refresh option[ref en-3] instead of reset. However, it still restores the default browser’s settings. Follow the guide to refresh Firefox:

1. Open the browser.
2. Type about:support in the address and bar and click Enter.
3. In the appeared Troubleshooting Information tab, find Refresh Firefox… button.
   

   

4. The dialog window pops up. Click Refresh Firefox again.

Method 6. Disable VPN

Some users reported that the problem occurs when using a VPN. Therefore, you should disable the connection via it and try downloading the file without it. If you need to download the file while being anonymous, you could try using a different VPN service, such as [rev id="Private Internet Access"].

Alternatively, you could also employ Tor browser to stay anonymous, but download speeds within the Tor network are abysmal, so you might have to wait a while, regardless of your internet connection capabilities.

Method 7. Reinstall Firefox

You can try to uninstall and reinstall Firefox to fix “Could not be saved because the source file could not be read” Firefox error.

• Type in Control Panel in Windows search and press Enter.
• Go to Programs > Uninstall a Program.
• Here, find Mozilla Firefox entry.
• Right-click on it and pick Uninstall.

  

• Follow on-screen instructions to finish the process.
• Now go to the official Firefox download page and reinstall the app.

If you have any questions regarding the "Source file could not be read" fix, or you are facing other difficult errors, please do not hesitate to contact us, and we will do our best to provide further assistance.