Navigate to your platform (e.g., /win64/ for 64-bit Windows or /mac/ for macOS) and select your language (e.g., en-US ).
To find a specific version, replace the version number in the URL (e.g., .../releases/45.0/ ). Download Firefox 12-51 52 Esr
This is expected. Modern HTTPS standards (TLS 1.3) and certificate authorities often reject Firefox 12-51. You can try enabling older TLS versions in about:config ( security.tls.version.enable-deprecated ), but this is a security risk. Navigate to your platform (e
: It was the last version to support legacy plugins like Java, Silverlight, and Adobe Acrobat (standard Firefox 52 and later dropped support for these). Navigate to your platform (e.g.