Fenix: [Bug] File downloads don't work when adblocker is installed

[AquaBytez]

While in private browsing mode, no downloads work. I'll get the prompt to download the file, but no visual feedback whatsoever after the download "starts". After a while, a message from the Android Download Manager will pop up, as follows

Fenix has the storage permission, and is allowed to install apks from unknown sources just in case.

For reference, my device is a OnePlus 6T A6013, running OxygenOS 9.0.13

[vesta0]

@AquaBytez I can't reproduce this. Would you please provide more information on file types you were trying to download or exact steps to reproduce? Thanks!

[AquaBytez]

After a lot of digging, this seems to be caused by AdBlockers, in my case, Blokada. As soon as the adblocker is disabled, downloads work again. The following blocklists are in use: Energized Blu, Goodbye Ads by Jerryn70 and Dan Pollock's hosts file.

This is a Fenix bug, as having the Adblocker enabled doesn't prevent other browsers from downloading files

[vesta0]

@AquaBytez does this only impact download in private browsing? If it's caused by adblockers then it should impact all downloads I think.

[AquaBytez]

I'm not able to reliably reproduce it outside of private browsing, but after a lot more testing, it seems like it also affects normal sessions.

If there's any way I can produce a log to make this easier to track down, let me know how to do so.

[vesta0]

@AquaBytez please let us know if you are still experiencing this issue. I suspect that only downloads on authenticated sites are still an issue (currently being addressed).

[AquaBytez]

Updated 15 minutes ago. Downloads still don't work.

[Coch3se]

I just tried to download an APK from GitHub that was giving me problems and it is working now.

[vesta0]

@AquaBytez what types of downloads still don't work? Could you provide steps to reproduce?

[AquaBytez]

https://imgur.com/a/ve3Mfq6

[vesta0]

@AquaBytez it would be super helpful if you could provide an example of a site that you are downloading from, and the file type.

[AquaBytez]

This doesn't work https://download.servo.org trying to download the android build results in the image above

[Coch3se]

@AquaBytez I was able to download your file https://imgur.com/qDJmK6t

[AquaBytez]

That's odd. Could you try this setup? https://imgur.com/a/bC1EXJQ

Because as soon as I turn off the app, everything works just fine.

[Coch3se]

@AquaBytez I can't download the file if I enable "Goodbye Ads" or "Dan Pollocks". With only "Energized Blue" enabled I have no problem with the download.

[AquaBytez]

I wonder which host is being blocked that prevents downloads from working.... At least we were able to narrow it down to those two lits.

[Coch3se]

Just got an update to both Blokada and Fenix and downloads are back to download unsuccessful after `5 minutes. I only have the "Energized Blu" host list active.

[thelazyoxymoron]

Experiencing the same issue, even when the AdBlock is off. While trying to download any file, whether in a private or a normal session (for example, through Firefox Send), it prompts asking whether I want to download or not, and immediately shows in the notification bar that the download was unsuccessful. Storage and Install from unknown sources permissions are given.

Platform: Android 9, Mi A1
AdBlock: https://www.f-droid.org/en/packages/org.jak_linux.dns66/

[nyanpasu64]

I think this may be related to a bug on Android. https://github.com/julian-klode/dns66/issues/31 . Enabling DNS66 and attempting a download, the download notification appears and disappears immediately.

Try excluding Firefox Fenix or Downloads Manager from your adblocker app.

Additionally this bug may be irrelevant on Fenix master, since https://github.com/mozilla-mobile/fenix/issues/1657 https://github.com/mozilla-mobile/fenix/commit/cbd811dcfb30c0333a110eedbe52b67b20d76360 was merged. Now Fenix no longer uses Android's download manager.

[thelazyoxymoron]

Experiencing the same behavior after excluding Firefox Focus and Preview from the AdBlock list. Crucially, I was able to download other files (for example, from Google Drive, or Yandex drive), but it's files from Firefox Send that's causing the issue.

I have installed the latest Firefox Preview that is available on the play store. This is definitely an unusual behavior. If no one else is able to reproduce this issue, I'll have to resign myself to thinking this has something to do with my phone itself.

[nyanpasu64]

@siddhugolu Firefox Send not working is a separate bug: https://github.com/mozilla-mobile/fenix/issues/3336

[thelazyoxymoron]

@jimbo1qaz Oh! Sorry for spamming then. I should've searched differently.

[NotWoods]

@siddhugolu Could you check to see if you can download the file using Reference Browser? It uses the new Gecko downloading system currently in Fenix master.

[thelazyoxymoron]

@NotWoods I was able to download the file using Reference Browser, but it downloaded a 12 byte garbage file (with the original filename), as reported in bug: #3336

[NotWoods]

Does that happen on other sites or just Firefox Send? If it's just Send we can close this issue since #3336 is tracking that.

[thelazyoxymoron]

@NotWoods I'm facing the download problem only with Firefox Send. Not sure whether OP is still facing the issue or not.

[NotWoods]

@AquaBytez Can you also try to reproduce on Reference Browser?

[pocmo]

QA: Can this still be reproduced? We recently changed the download manager implementation.

[thelazyoxymoron]

Tried uploading and downloading a file from Firefox send. While uploading works fine, downloading produces an error saying "Firefox preview can't download file of this type". Tried it with adblocker on/off as well as different files (i.e. jpegs and pdfs) and the issue remains the same.

[sv-ohorvath]

my device is a OnePlus 6T A6013, running OxygenOS 9.0.13

I cannot reproduce on a Galaxy S8, Android 9 device, with Blokada on. But given that the reporter has a custom OS it might be different.
@AquaBytez Please let us know if you still have this issue, if not we can close this.

[matfantinel]

I am still having this issue, on a Galaxy S10e with Android 9. Had the same on my previous Xperia XZ1c.

File in question was from Android Filehost.

[jerome-tgl]

I can download files on OnePlus 6T with Android 10, Firefox Preview 3.0.2 and Blokada 4.4.3, but the process is quite buggy.

Here's what happens when I tap a link to file on a webpage.

↓ Download (<file_size>)
<file_name>
              [Download]

Tapping Download:

✔ Download complete (<file_size>)
                           [Open]

NB: file_name and file_size is null if the file happens to be an image (and if the image is saved via a long press > download image)

Tapping the Open briefly displays an empty file preview (titled null) for PDF. For images, the native Android modal shows up and let me select an image app. Selecting the OnePlus gallery will open it but fails to display the image (Photo loading impossible).

But all files are actually saved into my Download directory, somehow.