There are no specific changes in the 19.1 installation that preclude it’s use on either of the platforms you mention having issues with. We no longer test on those platforms, and since they are no longer officially supported, we would not fix issues only found on them. But we do find it surprising that you have run into problems on either of those platforms (especially 2012 R2) and wonder if the issues you report are generic to the platforms themselves or just the specific machines you tested on.

Have you seen the same results on multiple machines of each O/S?

Have other developers installed on these platforms with success?