Error: Failed to check Content Document

[Voringran]

Hello,

I have an issue with Ace by Daisy, it seems to be unable to load and validate the epubs correctly. The screen loads for a bit and then an error pops up saying that it was unable to read a certain xhtml file (every time is a different one). It started doing this when I updated Ace by Daisy to the last version and I thought that that was the problem, but I just downloaded the previous one and it keeps appearing the same error. It happens with new epubs and epubs that I already validated previously, when I didn't have this issue.

I have a macOS M3 Sequoia 15.3.1, I've seen on some previous issues that someone had a similar error. I thought that maybe the problem is from the ePub file, but I've run the same ePub on another computer (windows) and Ace by Daisy worked perfectly and smoothly.

It has been happening for the last couple of weeks and I don't know what to do. Last week I validated an ePub and it took me half an hour (because it worked eventually, by putting on and on the file until it gave me a result).

[danielweck]

That's very interesting, would you mind privately sharing an EPUB that causes the issue? (I am a member of the core developer team at DAISY Consortium)
I too use MacOS Sequoia on modern Apple Silicon hardware. So far I have not been able to reproduce these types of bugs.

[Voringran]

Thank you for your quick response!

Unfortunately, I'm not able to send you the epub I'm working on right now for copyright reasons. I've tried to validate an epub that I did a few months ago and it keeps popping up the same error. This epub was already validated without any problems, so it doesn't seem like an error within the epub file.

I'm going to add two screenshots of the error: it's from the same epub, but each error seems to come from a different xhtml file.

[danielweck]

I understand, and I am happy to sign an NDA is this helps. Meanwhile, I will continue to try to reproduce the error at my end with various EPUBs, but so far I have been unsuccessful.

[Voringran]

I can send you the last ePub that I checked. It's a file without copyright that I did a few months ago: I validated it then and it worked perfectly, but now it doesn't.

I don't know if the issue really comes from the file itself, at least not my error in particular. It has happened with different epubs and only after I updated the program to its new version. Could it be a problem with the security and permissions of the computer?

[danielweck]

sounds like some combination of updated system-level restrictions, and Ace internal component upgrades (Electron probably)

my email is daniel.weck@gmail.com

[hadleyhendrix]

Hi! I am also having the same issue. I have never used DAISY before and just downloaded it a couple of weeks ago. I've been checking various epubs to test their validity, and I get the same error message. However, if I keep doing it enough times, it seems like it's able to work very occasionally. So, I've just continued to keep plugging it in and hoping it checks it. Would love to know if you were able to figure out a solution.

[danielweck]

Hello, unfortunately I am not able to reproduce the bug. I tried multiple times.

On my computer the publication validates in just over one second using the default Electron "runner" (this is the software component that actually executes the Deque Axe checks for each HTML document, inside a Chromium web browser engine / webview).

The legacy opt-in "Puppeteer" runner is still available via the command line: "ace" is an alias for "ace-electron", and "ace-puppeteer" still coexists, just in case, such as when we need to troubleshoot these kinds of obscure random bugs!

The Puppeteer runner is three times slower than the Electron one, when I check Voringran's EPUB (this performance difference is "normal", the default Electron runner is usually quite a bit faster).

Both runners complete successfully with identical reports.

Ace App GUI is itself built with the Electron application framework, so it only supports the Electron runner (not the Puppeteer one).

Would you mind testing Ace on the command line with both ace-electron and ace-puppeteer?
https://www.npmjs.com/package/@daisy/ace

You will need an installation of NodeJS https://nodejs.org

Thank you!

[hadleyhendrix]

Hi Daniel, thanks for responding. I went to the thread that @luisparravicini linked and saw you updated the Ace getting started page, which is where I downloaded Ace from originally. I reinstalled it from there and it's now working perfectly fine, so I think it just had something to do with what file I downloaded originally! Much appreciation for your time and help!

[danielweck]

Thank you so much for letting us know.
For new visitors, here is the relevant comment in another issue: #184 (comment)

[Voringran]

Hello, I also downloaded the update on the getting started page. Now it works perfectly! Thank you!