Let’s say you set up Doom Emacs from scratch for the first time, and you followed the instructions correctly and install the all-the-icons fonts when prompted, saw the icons properly displayed in the dashboard (launch window), but once you open a file, the status line starts showing random characters, instead of icons.
You need to install nerd-icons using
M-x nerd-icons-install-fontsbecause the doom-modline has switched from all-the-icons to nerd-iconshttps://github.com/seagle0128/doom-modeline/issues/310