Failed to setup root ca in firefox on macos
Author: kkunjasCreated Apr 20, 2026Updated May 27, 2026
mkcert -install The local CA is already installed in the system trust store! Installing in Firefox failed. Please report the issue with details about your environment at https://github.com/FiloSottile/mkcert/issues/new Note that if you never started Firefox, you need to do that at least once.
installed mkceert and nss through brew macos 26.3.1
Source: FiloSottile/mkcert