(I meant the update notification windows)

Please provide the build info from Help -> About, and details of your OS/DE

Otherwise can not confirm on Windows 10 Pro 64-bit en-US with
Version: 5.1.6.2 (x64)
Build ID: 07ac168c60a517dba0f0d7bc7540f5afa45f0909

the update check -> download button lands on the LibreOffice Still download page at an annotation appropriate to select the 64-bit download, .e.g http://www.libreoffice.org/download/libreoffice-still/?type=win-x86_64&lang=en-US&version=5.2.5

while on same system with an x86 build 
Version: 5.1.0.2
Build ID: ecd3574d51754b043f865cf5bafee286d24db7cc

the update check -> download button lands configured for an x86 32-bit build download, e.g. http://www.libreoffice.org/download/libreoffice-fresh/?type=win-x86&lang=en-US&version=5.2.5

So, this is correct and WFM with Windows builds. 

Also, update check download has never completed an automated download and update. It is planned, including incremental updates, but is not in any sense functional at this time. 

Landing at the download page is all that is supported for now.

https://de.libreoffice.org/download/libreoffice-still/
or
https://www.libreoffice.org/download/libreoffice-still/

It is correct that the download does not start immediately but the first seen link is just called "DOWNLOAD VERSION 5.2.5" and links to the x86 version - even if a x64-version was installed.
Therefore everyone with a x64 operating-system has to look for the x64-version to get no "downgrade from 64 to 32 bit".
For shure this is no real bug.
Maybe it would be helpful to note that the download is the x86 version withink the links description or mention a x64-link directly below.

(if an update appears it links to this webpage)

(In reply to Mike from comment #3)
> https://de.libreoffice.org/download/libreoffice-still/

Again, NEEDINFO

What Operating System (OS) and Desktop Environment (DE) are you working with? From the link above assume your locale is German speaking.

For the en-US builds, on the download pages for 5.2.5 Still the correct 32-bit or 64-bit build flavor is pre-selected, i.e. it Works For Me (WFM).

Excuse me, please.
I am from germany.
The computer I used has Windows 10 x64 (Build 14393.rs1_release.161220-1747) installed.
And I use Google Chrome [Version 56.0.2924.87 (64-bit)] as web-browser.
A click for an update opened this webpage.
If my mouse hovers the "VERSION 5.2.5 HERUNTERLADEN"-field you can see the link on the lower left side of the browser showing the x86-version:
http://imagizer.imageshack.com/img924/8780/K3O1Ak.png

(This link: "http://donate.libreoffice.org/de/dl/win-x86/5.2.5/de/LibreOffice_5.2.5_Win_x86.msi" - As you can see it is the x86-version)


In LibreOffice:
"Version: 5.2.5.1 (x64)
Build-ID: 0312e1a284a7d50ca85a365c316c7abbf20a4d22
CPU-Threads: 4; BS-Version: Windows 6.19; UI-Render: Standard; 
Gebietsschema: de-DE (de_DE); Calc: group"
(the updated version, I am sorry that I cannot tell you the exact version that caused this problem because of I already updated it)

Thank you. Back to UNCONFIRMED

In fact the update notification does not link in dependency to the installed version.
Therefore I was linked to this page:
https://de.libreoffice.org/download/libreoffice-still/
But it should have linked me to this one:
https://de.libreoffice.org/download/libreoffice-still/?type=win-x86_64&version=5.2&lang=de
(The link shown in "Windows x86_64 (Vista or newer required)" below "Operating Systems" if I remove the "de."  in the URL)

I think that should explain the problem.
The update notification of LibreOffice links in dependency of the language to the correct site but not in dependency to the architecture. I did not test this for other Operating Systems but in Windows x64 a x64-Version of LibreOffice does definetivly do that.

Unable to decide if this comes from the check.php script, or is an issue from rework the Website.

Opened a Redmine issue for this. 

https://redmine.documentfoundation.org/issues/2176

@Mike, * 

Did you still have an issue for the 5.3 release?

ping mike..