You might find more compatible extensions at the Legacy Collector dump or by installing the Classic Add-ons archive extension. The following are the last versions of certain extensions for the 28.x series: HTTPS Everywhere The following are the last versions of certain extensions for the 27.x series: HTTPS Everywhere
WINDOWS XP BROWSER UPDATE
WINDOWS XP BROWSER INSTALL
Officially, Pale Moon does not support Windows XP anymore. Pale Moon/New Moon for Windows XP - Matej Horvat Pale Moon/New Moon for Windows XP