IEEE Xplore + institutional VPN: 418 in citation export, while direct access still works

jf235 · 2026-04-10T19:28:15+00:00

Hi, I’m having an intermittent problem saving items from IEEE Xplore with Zotero Connector.

These are the errors I get:

[JavaScript Error: "HTTP request to https://ieeexplore.ieee.org/rest/search/citation/format?recordIds=11367048&fromPage=&citations-format=citation-abstract&download-format=download-bibtex rejected with status 418"]

[JavaScript Error: "Method saveAttachmentFromResolver failed
@moz-extension://3134f743-a7df-4dd6-9bc1-7c3c9888c5c7/connector.js:339:49
" {file: "[object Object]"}]

Report ID: 1223677753

What I found so far:

This happens when using my university VPN/institutional access
Without the VPN, Zotero works
With the VPN, the article page and PDF still work
The IEEE Xplore Cite This button also works
I can also open the citation export URL directly in the browser

So the problem seems specific to the Zotero Connector save flow for IEEE Xplore, not to article access in general.

My suspicion is that Zotero is using a different request flow from the site’s own citation export flow, and that this is failing under the VPN/institutional session context.

Xiao_13 · 2026-04-12T12:28:58+00:00

[JavaScript Error: "_0x43e525[_0x38db77(...)] is not a function" {file: "jar:file:///C:/Users/Xiao/AppData/Roaming/Zotero/Zotero/Profiles/gnblri08.default/extensions/zoterogpt@polygon.org.xpi!/chrome/content/scripts/zoterogpt.js" line: 1}]

[JavaScript Error: "_0x43e525[_0x38db77(...)] is not a function" {file: "jar:file:///C:/Users/Xiao/AppData/Roaming/Zotero/Zotero/Profiles/gnblri08.default/extensions/zoterogpt@polygon.org.xpi!/chrome/content/scripts/zoterogpt.js" line: 1}]

[JavaScript Error: "_0x43e525[_0x38db77(...)] is not a function" {file: "jar:file:///C:/Users/Xiao/AppData/Roaming/Zotero/Zotero/Profiles/gnblri08.default/extensions/zoterogpt@polygon.org.xpi!/chrome/content/scripts/zoterogpt.js" line: 1}]

[JavaScript Error: "uncaught exception: Object"]

[JavaScript Error: "uncaught exception: Object"]

[JavaScript Error: "HTTP GET https://ieeexplore.ieee.org/rest/search/citation/format?recordIds=11062661&fromPage=&citations-format=citation-abstract&download-format=download-bibtex failed with status code 418"]

[JavaScript Error: "HTTP GET https://ieeexplore.ieee.org/rest/search/citation/format?recordIds=11062661&fromPage=&citations-format=citation-abstract&download-format=download-bibtex failed with status code 418"]

[JavaScript Error: "HTTP GET https://ieeexplore.ieee.org/rest/search/citation/format?recordIds=11062661&fromPage=&citations-format=citation-abstract&download-format=download-bibtex failed with status code 418"]

[JavaScript Error: "The connection to wss://stream.zotero.org/ has terminated unexpectedly. Some data may have been transferred."]

[JavaScript Error: "WebSocket connection closed: 1006 "]

[JavaScript Error: "HTTP GET https://ieeexplore.ieee.org/rest/search/citation/format?recordIds=10756650&fromPage=&citations-format=citation-abstract&download-format=download-bibtex failed with status code 418"]

[JavaScript Error: "HTTP GET https://ieeexplore.ieee.org/rest/search/citation/format?recordIds=11062661&fromPage=&citations-format=citation-abstract&download-format=download-bibtex failed with status code 418"]

[JavaScript Error: "HTTP GET https://ieeexplore.ieee.org/rest/search/citation/format?recordIds=11062661&fromPage=&citations-format=citation-abstract&download-format=download-bibtex failed with status code 418"]

[JavaScript Error: "HTTP GET https://ieeexplore.ieee.org/rest/search/citation/format?recordIds=11062661&fromPage=&citations-format=citation-abstract&download-format=download-bibtex failed with status code 418"]

appName => Zotero, version => 7.0.32 (x64), os => Windows 11 26100, locale => zh-CN, extensions => Jasminum (1.1.21, extension), Translate for Zotero (2.3.16, extension), Awesome GPT (3.1.2, extension), Scholaread 靠岸学术 (1.2.9-0, extension, disabled)

It seems that I have encountered the same error.

aborel · 2026-04-12T13:02:42+00:00

Try to disable all plugins and see if the problem still happens. If it happens without any plugin, upgrade Zotero to the latest version and follow all the steps listed at https://www.zotero.org/support/reporting_problems

If the problem vanishes when you disable all plugins, re-enable them one by one until you can identify which plugin causes/enables the error. Then report to the plugin developer so that they can address the issue.

jf235 · 2026-04-12T19:25:48+00:00

Thanks, here is a cleaner report with the requested details.

Environment:

* Zotero: 9.0 (64-bit)
* Zotero Connector: 5.0.200
* OS: Ubuntu 24.04.4 LTS
* Browsers tested: Firefox and Chrome
* Other browser extensions: all disabled except Zotero Connector

Report ID: 781727327

Steps to reproduce:

1. Connect through my university institutional VPN / proxy access.
2. Open an IEEE Xplore article page.
3. Click the Zotero Connector button to save the item.
4. The save fails during citation export.

What happens:

* Zotero shows the message: “An error occurred saving with IEEE Xplore. Attempting to save using Embedded Metadata instead.”
* In the browser console, I can see the request to the IEEE Xplore citation export endpoint failing with HTTP 418.
* At the same time, the IEEE Xplore article page itself still loads normally.
* The PDF still opens normally.
* IEEE Xplore’s own “Cite This” export works.
* Opening the citation export URL directly in the browser also works.

What I expected:

* Zotero Connector should save the IEEE Xplore item normally, rather than failing on the citation export request and falling back to Embedded Metadata.

Additional notes:

* I tested this in both Firefox and Chrome and saw the same problem.
* I am not using other browser extensions besides Zotero Connector.
* Given that other users have reported very similar IEEE Xplore 418 failures in the last few days, this may not be specific to my VPN setup alone. It may indicate a broader regression or a recent change in how IEEE Xplore is handling citation export requests from the Connector save flow. Such as:
- https://forums.zotero.org/discussion/130853/problem-exporting-papers-from-ieee-xplore#latest
- https://forums.zotero.org/discussion/130852/error-whilst-saving-with-ieee-xplore-system-is-attempting-to-use-embedded-metadata#latest

adamsmith · 2026-04-12T19:44:26+00:00

418 is wild.... I'm not sure I've ever actually seen that.
I'm wondering whether that's an anti-bot measure that tries to confuse standard anti-bot evasion using an unusual error.

A debug ID from the Zotero connector might help, though less likely if I'm right about the anti-bot measure: https://www.zotero.org/support/debug_output#zotero_connectors_firefox_chrome_and_safari

Are you able to test directly on campus/the IP range, without the VPN? And what type of VPN are we talking about -- a full VPN with Cisco, OpenVPN, Wireguard or the like? Or some webVPN service that works in the browser?

jf235 · 2026-04-12T20:09:31+00:00

Hi @adamsmith, thanks for looking into this.

I'm using a full OpenVPN connection to my university -- not a webVPN. I haven't tested on campus yet, will try to do that.

In the meantime, I've been looking into the translator source code. One thing I noticed is that the GET endpoint still works via direct browser navigation (you can open it in a tab and see the BibTeX), but it returns 418 when called via XHR. This might be related to IEEE's bot protection distinguishing between navigation and programmatic requests (different Sec-Fetch-Mode headers).

Comparing the Connector's request with IEEE's own "Cite This" in the Network tab:

* Connector: GET /rest/search/citation/format?recordIds=... via XHR -> 418
* IEEE frontend: POST /rest/search/citation/format with JSON body ({"recordIds":["10255275"],"download-format":"download-bibtex","lite":true}), Content-Type: application/json, and X-Security-Request: required -> 200

I patched my local IEEE Xplore.js translator to use POST with the new payload and headers, and the metadata now saves correctly, no more 418, no fallback to Embedded Metadata.

However, the PDF attachment still fails to download (saveAttachmentFromResolver error). I haven't investigated this part further yet :(

theonlyJR7 · 2026-04-20T06:49:26+00:00

I had the same problem last week.
Now it seems to be fixed.
At least I'm not able to reproduce the issue anymore.