Firefox Bug: File could not be saved, because the source file could not be read.
In Windows, using Firefox (for me it was 3.6.3), I use to get an error whenever I download a large file (over 200 MB), Firefox launches an warning error saying "file could not be saved, because the source file could not be read." This is quite an annoying bug for Firefox, and I've seen it on many computers. Perhaps it's not something Firefox can easily fix, because it might be specific to each user's situation (regardless, I still think Firefox should look into it).
This problem seems to make me unable to download or save most big files that I need. Seems to target files over 70 MB (I was able to download a 60 MB file). However, there are various bugs that can cause this, so one solution does not fit all.
For many situations, the bug seems to happen when the download is almost finished.
c:\DOCUMEN~1\CEW~1\Locals~1\Temp\blablalba.zip could not be saved, because the source file could not be read.
Try again later or contact an administrator.
I've tried multiple ways to fix the problem, on my computer I've been able to fix it using the following methods, but for some people I cannot fix the problem. (So if our readers have suggestions, I can update and put new solutions)
Firstly, you should find the following folder in windows explorer.
In Windows 7, this is what the path looks like. In older Windows, it could be under C:\Documents and Settings.
( is your username of the administrator account)
Usually the default is the profile you use, it is named arbitrarily. If you don't see AppData, you need to go into Organize > Folders and Search Options > View tab > "Show Hidden Folders" should be enabled.
Make sure Firefox is closed before you attempt any of the following.
Solution #1: In here, you will find a history.dat or in future versions places.sqlite. It's possible that it is set to Read-Only, right-click properties, and then uncheck read-only. Alternatively, if you don't mind losing your history, you may delete the files.
Solution #2: You may find compreg.dat or compreg.sqlite is corrupted. Try deleting this file and restarting Firefox.
Solution #3: Type about:config in address bar, in the filter field type browser.download. There should only be TWO bold entries, browser.download.dir and browser.download.lastDir, I had a third bold entry, and I reset that one, I changed my browser.download.dir and my downloading problem was solved (at least in my case)!
Solution #4: You should try to disable virus scanning using about:config, accept the warning, then in the Filter bar type browser.download.manager.scanWhenDone and double click it to make it false.
Solution #5: This could also be an add-on extension problem. Try Uninstalling various add-ons. Mainly, anything relating to downloading, history, or files. For example, I had DownloadThemAll, perhaps there was a problem. "Download helper" might also cause problems.
Solution #6: Try uninstalling and reinstalling Firefox after deleting profile folder.
Solution #7: Also test to make sure it works with Google Chrome. It's possible that an anti-virus or Spybot S&D may be interfering with downloads of big files.
Solution #8: Try downloading via "Save Link As..." because it's possible it's downloading to a bad area without permissions. (There could be a permission problem)
Solution #9: (possibly a last resort) If you don't mind losing all your bookmarks, passwords, history, cookies, everything (you may also save them), you should try deleting your profile folder. (XMarks extension can help you save your passwords/bookmarks). Alternatively you can right-click and uncheck "read only" for the entire folder, and apply it to all files below.