4th Experimental - Important updates for Firefox 53 (and earlier!)
Pre-release
This update has important corrections needed for Firefox 52 regarding error pages (for bad addresses). It has also essential changes to support the changes in the _Developer Tools_ in Firefox 53 towards a non-XML setting. It also restores for the _Animation Inspector_ in Firefox 52a2. It has corrections to about:sessionrestore and about:welcomeback in all supported versions since Firefox 38. It also has corrections for the support for Containers Tabs experiment in Firefox 52 and 53.
There are many other changes and corrections (e.g., in about:newtab). I am hopping the solution for #30 is included here too! (Please let me know if #30 is solved with this.)
_Please note there are no changes in the project area (i.e., the source code will not match). Only the .xpi (the installation file) has the corrections._