All files corrupted after download

[pastoweb]

Hello, since a few days all the files downloaded via jdownloads result corrupted.
Redownloading them via FTP they are ok, while downloading via jdownloads they seem some smaller than the original and fail opening. This is happening with files of all dimensions, from 120kb to 40mb

Using Joomla 5.4.6 and jdownloads 4.1.5

Direct download from a link to a file in a joomla article not using Jdownloads seems ok

What could be happened?

[ColinM]

Hi
This is strange. I am also using jD 4.1.5 but For Joomla it is version 6.1.2.  So I suggest that after taking a backup that you upgrade Joomla to 6.1.2
ColinM

[pastoweb]

I have many components involved in my site so I can't easily do a joomla major upgrade now.

We have been hacked in the past weeks so we had to enforce some joomla configurations and reset files permissions.

Is there any joomla or cloudflare or server configuration that may be interfering with the download in such a way?

[pastoweb]

Tryed to activate direct download in jdownloads disabling the "Send Downloads using the PHP Script" options, but downloads just don't work (maybe because of URL rewrite rules)

[ColinM]

Hi
Did you make an Akeeba backup of your site.  Not sure that Joomla works with Cloudfare - you should check with the Cloudfare people.
jDownloads just needs a regular Joomla site, nothing special
Which version of jDownloads are you using? Similarly which version of Joomla?
ColinM

[pastoweb]

As I wrote in the first message I'm using a "regular" Joomla 5.4.6 (now.7) and jdownloads 4.1.5
I don't understand what is the point with akeeba, anyway I don't use it
Of course Joomla works under Cloudflare, as any other website in the world... even the official joomla website uses it for the forums

I also verified that zlib.output_compression is off in my server (https://www.jdownloads.net/documentation?view=article&id=180:strange-faults-did-you-know-that&catid=28)

It's of course some strange behaviour happening when passing through jdownloads php script whith specific server or firewall conditions, just need help to address the right setting

[pastoweb]

Ok we did some steps forward: cloudflare is NOT part of the problem, bypassing it the issue remains

The issue only appears using chrome, with firefox files are downloaded correctly

You can try yourself by downloading any file from this page with chrome and with firefox:
https://formalms.org/download/all-downloads/category/11-forma-lms-4-0-x.html

[ColinM]

pastoweb
I always use Firefox!! And yes the download was ok.   
Do not have Chrome installed as it is not my favorite browser!!. But I do have on my Laptop. So I have just used it and download link worked OK!!!
ColinM
PS The version of Chrome on my Laptop is an old one - maybe your version did not install properly or it has been corrupted? Or as a result of the hacking

[Arno]

Hi pastoweb,
thanks again for the detailed report and for testing with different browsers.

What you describe is plausible and helped us narrow this down: when Firefox works but Opera/Chrome fails, it usually points to differences in how browsers handle partial-content (Range) downloads and stream validation. In that situation, a download path can appear fine in one browser while another browser marks the same transfer as corrupted because it is stricter about byte ranges and response consistency.

So this is why it does not always reproduce everywhere:
1. It depends on browser behavior (Firefox vs Chromium-based browsers).
2. It can depend on specific server/proxy/WAF conditions and response handling.
3. It may only be visible when files are delivered through the PHP download script path, not when downloaded directly.

Based on your report, we prepared a fix in the download streaming/range handling path to make this behavior more robust across browsers and environments.

Important:
1. You are not doing anything wrong.
2. This is not necessarily caused by Cloudflare alone (your bypass test was useful).
3. The issue can still be real even if another user cannot reproduce it on a different stack/browser/version.

We will publish this fix in jDownloads 4.1.6 (planned later today). 
After updating to 4.1.6, please test again with Opera/Chrome and Firefox and let us know if the ZIP integrity issue is fully resolved on your site.

Thanks again for your precise troubleshooting feedback. It directly helped us identify and address this.

[pastoweb]

Hello Arno, thanks for looking into it. I still don't see any new release either on your website or in joomla extension manager, when do you think it will be available?

[Arno]

Hi,
sorry for the delay. I had some trouble in the last days.