Firefox 55, extension conflicts, virtual tabs (startup performance) and Firefox not responding

55.0 and 55.0.1 reveal conflicts that were not apparent with 54.0.1. No surprise there, however …

… some of the conflicts cause Firefox to stop responding and it becomes necessary to kill the firefox process, which is extremely rare on FreeBSD.

Compatibility reports for three extensions, all of which are now disabled:

  1. Violentmonkey
  2. Tab Memory Usage
  3. Tab Suspender (Tab Unloader) also known as Tab Suspender (memory saver).

Two of those – Tab Suspender (Tab Unloader) and Violentmonkey – are classified as WebExtensions, compatible with Firefox 57+.

Virtual tabs

Mozilla bug 906076 - (lazytabs) Virtual tabs - lazily create linkedBrowser and other dependent elements for tabbrowser tabs to improve startup performance (RESOLVED FIXED)

The difference in performance between 54.0.1 and 55 was remarkable.

However: from the details that I observed before making compatibility reports, I suspect that something around 906076 increases the likelihood of Firefox becoming unusable in some extension conflict situations.

Thoughts?

This bug caught my eye: 1364847 - WebExtension based add-ons should never mass insert browser elements for lazy browsers., might it be related?