Well, it is a mystery. Perhaps it is related to the fact I use Windows 10. When I do a fresh install of version 1.0, it tries to put the game into C:\Program Files (x86)\Matrix Games. When I try to install the patch, it tries to put the patch into C:\Games (which is where all my other AGEOD games typically go). But no matter which folder or sub-folder I try to install the patch in, it always creates a set of folders called "Thirty Years War" with a "TYW" sub-folder. The Thirty Years war folder and TYW sub-folder are always created, regardless of whether I install into the "Games" folder, the "Thirty Years War" folder or the "TYW" subfolder. They sit alongside each other and I have to manually drag the new files onto the old. Then - and only then - do I get the message prompting me to overwrite files - it never happens during the actual installation, only when I manually try to copy the new over the old.
Again, maybe it is Windows 10 related, since it seems you are using Windows 7 and I know there have been issues related to how Windows 10 places things. Anyway, I have done about ten uninstalls and fresh installs, and no solution - I am always getting messed up RGD conversion icons, sometimes multiple Contribution icons as well.
I am checking with Slitherine Help Desk to see if I am missing something. I will report back what I find.
EDIT - we seem OK now. My opponent restarted and it works fine. Must have been a corrupt file he sent me.