This version of macOS is affected by the certificate issue. I would highly suggest installing a version of Linux or a newer version of macOS instead. Even Firefox ESR was discontinued from Mavericks a while ago. Mavericks is aging, and there is no software support anymore. I do not recommend this macOS version for the same reasons as Mountain Lion. This patcher has been discontinued by the developer.

You can tell by seeing if your model has a *. NexPostFacto (64 bit) (ATI GPU ONLY) If your mac is equipped with ONLY an ATI X1300/1600/1900 GPU, you can run this patcher. If you need to use a Mac with this version of macOS, I would suggest using Linux instead. I do not recommend using this operating system in the current year. NexPostFacto (64 bit) (ATI GPU ONLY) This patcher has been discontinued by the developer. NexPostFacto (32 bit) If your Mac is equipped with ONLY an ATI X1300/1600/1900 GPU, it is highly recommended to use the fully 64-bit version. Unsupported Macs (Macs that can run it using a patcher) Model Supported Macs (Macs that can run it natively) Modelġ3″ from Mid 2009 or later, 15″ from Late 2007 and newer, 17″ from Late 2007 and newerġ3″ aluminum from 2008, 13″ from 2009 and newer This information is also available in the #faq channel in the Unsupported Macs Discord Server. This is a guide of how to install unsupported macOS and OS X versions on your Unsupported Mac.

Running big sur on unsupported mac