Firefox 3.6 is 13+ years old. It lacks modern security certificates (TLS 1.2/1.3), rendering most of the modern web (YouTube, Facebook, Reddit, Gmail) inaccessible or broken. Do not use this as your daily driver.
The Ultimate Guide to Downloading and Running Mozilla Firefox 3.6 download old version of mozilla firefox 3.6
: It lacks support for modern standards like TLS 1.2/1.3 , meaning most secure websites (HTTPS) will fail to load entirely. It also predates modern HTML5 and CSS3 features. Firefox 3
Never log into bank accounts, email, or social media using an outdated browser. Use it only for the specific task or legacy site you need. download old version of mozilla firefox 3.6