2 ms·
Looking at the version history, support for version 52 ESR ended in September 2018. Since that version was the last supported version with XUL, the lack of XUL
by cbmuser 5y ago
Looking at the version history, support for version 52 ESR ended in September 2018.
Since that version was the last supported version with XUL, the lack of XUL after that might be one of the reasons.