Corel Graphics Suite 12 installed on Windows 8.1 Pro - Issues

I've recently upgraded from Windows XP to Windows 8.1 for security reasons (Microsoft dropping support for XP). Corel 12 installed just fine and operates almost as good as on XP. I have only two issues that I've noticed so far:

1) I have been unable to install Corel 12 Service Pack 1 and the MultiPatch. Neither will install and so I am without the benefit of the host of little fixes that solve little annoyances.

2) Some fonts are broken. This is very much like the Security Update back in that people had on Win XP and Win 7 back in '12.  The difference here is that some of the installed fonts are not usable in Corel but they do work everywhere else. Obviously not the same Windows Update issue and I can find no information anywhere on how to fix it. Most of them are relatively innocuous ones that I don't really use anyway, but one is the corporate font chosen by a very important client and is used on every piece of art I have on file for them - years worth of files. 

I am NOT AT ALL interested in upgrading past Corel 12 unless it is absolutely necessary in order to start using those fonts again. What I really need is a fix so that I can keep using Corel Graphics Suite 12 to my hearts content.