Frequent error messages from Kobo's content server?

salty-horse · 01-06-2026, 02:20 AM

In the past few weeks, I've been getting a lot of "400 Bad Request" errors when trying to download ACSM files from the Kobo store.

(The URL for Adobe DRM content server is https://acs4.kobo.com/fulfillment/URLLink.acsm)

It usually works after waiting several minutes, but is annoying.

Has anyone else noticed this? Do you know if Kobo are aware of the problem?

Aleron Ives · 01-06-2026, 03:09 AM

How many weeks is a few? I downloaded multiple books 2 weeks ago and didn't have any problems getting the ACSM files, but I didn't download any last week...

salty-horse · 01-06-2026, 03:12 AM

No earlier than 14 days. It happened very frequently in the past 7 days.

RobertJSawyer · 01-06-2026, 05:38 PM

It happens to me all the time when I use Google Chrome under Windows 11. It doesn't happen to me ever when I use Microsoft Edge under Windows 11.

DNSB · 01-06-2026, 06:25 PM

For what it may be worth, I haven't noticed the issue with using Firefox under Windows 11 or Linux.

salty-horse · 01-07-2026, 05:28 AM

From tests in other browsers, private mode browsing, and on the command line, I think the Kobo server doesn't like the cookie the browser is sending when it's logged in.
Without the cookie, it works fine.

01-06-2026, 02:20 AM	#1
salty-horse Wizard Posts: 2,312 Karma: 21216368 Join Date: Sep 2008 Device: Kobo Clara 2E	Frequent error messages from Kobo's content server? In the past few weeks, I've been getting a lot of "400 Bad Request" errors when trying to download ACSM files from the Kobo store. (The URL for Adobe DRM content server is https://acs4.kobo.com/fulfillment/URLLink.acsm) It usually works after waiting several minutes, but is annoying. Has anyone else noticed this? Do you know if Kobo are aware of the problem?

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01-06-2026, 03:09 AM	#2
Aleron Ives Wizard Posts: 1,818 Karma: 17000000 Join Date: Sep 2022 Device: Kobo Libra 2	How many weeks is a few? I downloaded multiple books 2 weeks ago and didn't have any problems getting the ACSM files, but I didn't download any last week...

01-06-2026, 03:12 AM	#3
salty-horse Wizard Posts: 2,312 Karma: 21216368 Join Date: Sep 2008 Device: Kobo Clara 2E	No earlier than 14 days. It happened very frequently in the past 7 days.

01-06-2026, 05:38 PM	#4
RobertJSawyer Guru Posts: 757 Karma: 4306712 Join Date: Jun 2006 Location: Toronto Device: Kobo Libra 2, Clara 2E, and Clara HD; Kindle PaperWhite	It happens to me all the time when I use Google Chrome under Windows 11. It doesn't happen to me ever when I use Microsoft Edge under Windows 11.

01-06-2026, 06:25 PM	#5
DNSB Bibliophagist Posts: 49,464 Karma: 174632678 Join Date: Jul 2010 Location: Vancouver Device: Kobo Sage, Libra Colour, Lenovo M8 FHD, Paperwhite 4, Tolino epos	For what it may be worth, I haven't noticed the issue with using Firefox under Windows 11 or Linux.

01-07-2026, 05:28 AM	#6
salty-horse Wizard Posts: 2,312 Karma: 21216368 Join Date: Sep 2008 Device: Kobo Clara 2E	From tests in other browsers, private mode browsing, and on the command line, I think the Kobo server doesn't like the cookie the browser is sending when it's logged in. Without the cookie, it works fine.

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