Use an info icon same to the one in the Proton theme of Firefox itself, for network error pages.

Reduce (deactivate) mis-detection of the sidebar position on some unstable cases: leftside non-primary and high-dpi screen.

Update scrollability status of the tab bar even if there are some 'hidden via WebExtensions API, but visible by CSS hack' tabs.

Outdent tab via API correctly when a child tab is outdented to the root level with its descendants.

Fix unexpectedly invisible children when a parent tab is restored and collapsed tabs are re-attached to the restored parent.

Apply given colors to the toolbar button icon, menu icons and the sidebar header icon, if the theme provides rich information (ex.

Add a secret option to deactivate API for other addons: APIEnabled.

Collapse tabs dropped onto a collapsed tree correctly, when the drop target parent tab is kept collapsed by TST Lock Tree Collapsed.

Apply container information saved by Container Bookmarks correctly for tabs opened from a bookmark folder by the 'Open All as Tree' context menu command.

Revert to firefox 56