when I try to download 3d unity on my iMac on unity hub it will say failed to install 3d unity or something like that and it will bring me back to the first step of installing 3d unity am using an iMac 27-inch Late 2012 with macOS Mojave version 10.14.6 with a 2.9GHz quad-core Intel Core i5 processor (Turbo Boost up to 3.6GHz) with 6MB L3 cache and 8GB of 1600MHz DDR3 memory and 1TB (7200-rpm) hard drive and a NVIDIA GeForce GTX 660M graphics processor with 512MB of GDDR5 memory that should be enough for 3d unity to work right?