This works for 55.0.2883.91 for me.  Can you go to https://sites.google.com/a/chromium.org/dev/for-testers/providing-network-details and follow the instructions to get us a log?  Thanks!

Please kindly find the network log as attached and video here: https://youtu.be/fIUJnCXM5n4
Thanks

Deleted: net-internals-log.json 5.6 MB

net-internals-log.json 5.6 MB View Download

This is a site issue. Here is what happens:

1. I had the same problem when downloading from mediafire now, On android, http request and response headers are:

t=1133 [st=106]        HTTP_TRANSACTION_SEND_REQUEST_HEADERS
                       --> GET /bokfiobz3skg/6jnbg2g2iiowj29/.minecraft.rar HTTP/1.1
                           Host: download1679.mediafire.com
                           Connection: keep-alive
                           Upgrade-Insecure-Requests: 1
                           User-Agent: Mozilla/5.0 (Linux; Android 7.0; Nexus 6P Build/NBD91K) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/55.0.2883.91 Mobile Safari/537.36
                           Accept: text/html,application/xhtml+xml,application/xml;q=0.9,image/webp,*/*;q=0.8
                           Referer: http://www.mediafire.com/?6jnbg2g2iiowj29
                           Accept-Encoding: gzip, deflate, sdch
                           Accept-Language: en-US,en;q=0.8,zh-CN;q=0.6
                           Cookie: [148 bytes were stripped]
t=1133 [st=106]     -HTTP_TRANSACTION_SEND_REQUEST
t=1133 [st=106]     +HTTP_TRANSACTION_READ_HEADERS  [dt=102]
t=1133 [st=106]        HTTP_STREAM_PARSER_READ_HEADERS  [dt=52]
t=1185 [st=158]        HTTP_STREAM_PARSER_READ_HEADERS  [dt=50]
t=1235 [st=208]        HTTP_TRANSACTION_READ_RESPONSE_HEADERS
                       --> HTTP/1.1 302 Found
                           Location: http://www.mediafire.com/?6jnbg2g2iiowj29
                           Content-Length: 0
                           Connection: Close

So somehow mediafire redirects the url to http://www.mediafire.com/?6jnbg2g2iiowj29 on the device.
On desktop, I saw a 200 response code with the correct file path.


2. Now i checked the "Request desktop site" box, i reload the page. When clicking the download button, it opens a new tab with the url: http://www.mediafire.com/?6jnbg2g2iiowj29. 
However, this doesn't happen on desktop. So I started to suspect this is an issue related to cookie.

3. Now i go to site settings, clear the cookies for mediafire.com, and reloads the page.
The download successfully work this time.


So obviously there is some cookie issues at the server side. Not a chrome issue. Jon, do you know who can help us reach out to mediafire?

Issue 718706 has been merged into this issue.

I will reach out to mediafire. Min, Can you clarify what you are seeing?

On desktop
-The download always succeeds

On Android
-Using the mobile site, the download doesn't work. 
-Using "Request desktop site", the download still doesn't work.
-Clearing cookies, the download works for both

Is that correct?

I am not able to get it to download successfully even after clearing cookies. What I do see is that an infobar appears to be popping up, but it instantly gets removed.

Yes, this is the behavior I saw. However, I am not able to reproduce the issue on my device.

It is possible that after clearing the cookies, the download will work fine forever, or mediafire has fixed the issue (But i don't think so as we are still getting user feedbacks on this)

As I said in comment 7, I cannot download even after clearing cookies. Can you give me repro steps for how you got it to work?

which infobar?  I am able to download the link successfully, so I am not seeing any infobars.

Can you grab a net log?