Release v1.6.34
Context of the Issue
Firefox currently has a long-standing bug affecting filterResponseData when a tab switches from a remote=true context to a remote=false context.
This situation occurs mainly when navigating from or to certain internal about: pages. When that transition happens, Firefox can unexpectedly crash the response filter, breaking any extension relying on it.
Relevant Firefox bug reports:
// // https://bugzilla.mozilla.org/buglist.cgi?quicksearch=filterResponseData
// // https://bugzilla.mozilla.org/show_bug.cgi?id=1982934
// // https://bugzilla.mozilla.org/show_bug.cgi?id=1806476
// // https://bugzilla.mozilla.org/show_bug.cgi?id=1561604
What the Workaround Does
To avoid triggering the Firefox crash, the extension monitors whenever a tab loads an internal about: page. Some about: pages are harmless — for example about:newtab, about:home, etc. — and these are whitelisted.
However, some about: pages switch the tab to a non-remote context that breaks filterResponseData, and Firefox does not handle this transition safely. When the extension detects one of these problematic pages, it temporarily tags the tab as “unsafe”.
How the Fix Works
Detection phase
When a tab loads an about: URL, the extension checks whether it is one of the known safe ones (whitelist).
If it is safe → nothing to do.
If it is not safe → the tab is flagged as “needs workaround”.
Transition handling
As soon as the user leaves the problematic about: page:
The flag is removed.
Before loading the actual target page, the extension redirects the tab to a local extension page (uDarkTools.htm).
This local page runs in a stable remote=false context.
From there, the final URL is redirected cleanly.
Why this solves the problem
By forcing the navigation to pass through one extension page first:
We avoid the dangerous Firefox context switch that crashes filterResponseData.
The extension ensures that the final page is loaded in a context where filterResponseData is fully operational.
The redirection occurs before the target page begins loading, so there is no visible flicker and no functional impact for the user.
In short
Firefox crashes the response filter when moving out of some internal pages.
The extension now intercepts that transition and routes the navigation through a safe internal extension page, ensuring that filterResponseData continues working reliably.