axe DevTools induces a JS crash on any webpage relying on rollbar.js (error monitoring JS library)

[Rastagong]

Product

axe Extension

Product Version

axe DevTools 4.117.1 (based on axe-core 4.10.3) on Firefox 146.0.1

Latest Version

• I have tested the issue with the latest version of the product

Issue Description

Expectation

With axe DevTools enabled, I should be able to visit any webpage without inducing a page-wide Javascript crash.

Actual

When the visited webpage relies on the rollbar.js library (Rollbar seems to be a SaaS error monitoring platform), a crash occurs systematically when visiting with axe DevTools enabled: Error: Permission denied to access property "_rollbarOldOnError"
See the linked issuue on the rollbar.js repository: rollbar/rollbar.js#839

How to Reproduce

As of December 30, 2025, affected webpages include wise.com and the gog.com storefront. On gog.com, the crash prevents the login form from opening correctly.
Disabling the axe DevTools extension immediately stops the issue.

[WilcoFiers]

Ohh yikes. Yes that sounds like a significant problem. I've spent a bit investigating. I can confirm the problem, but I haven't got a clue yet as to why this is happening. I can't think of any reason why it might. That simply loading the extension prevents a page from functioning correctly is indeed concerning. We'll prioritize this issue. Thank you for bringing this up!

[straker]

Tested this using the Chrome extension and there was no issues. This seems like it only affects the Firefox DevTools extension.

[straker]

Tested loading https://docs.rollbar.com/docs/browser-js#quick-start before axe-core and after axe-core on a simple page and got no issues