Board Thread:Support Requests - Designing Your Wiki/@comment-45308935-20200724094450/@comment-23989026-20200724170611

The favicon is stored as

As per the help page, the new favicon must be stored as a .ico This file must be saved in ICON format, using software designed for generating .ico files -- simply renaming a .jpg/.gif/.png file with an .ico extension will not work

The help page links to a Google search for favicon+generator