Where did you install the game? Program Files (x86)?
This is getting to be one of my most pointed to threads:
CapnScurvy's Windows10; Large Address Aware; SH4 Install thread. He talks about the Large Address Aware applet for use on SH4.exe, but also about installing the game on a Windows 10 computer. Try the Capn's advice, and see how you make out.
Also, while FotRSU is based on TMO 1.7, there is a TMO2.5 (and Small Patch) that would have more "fixes" in it, and probably be better to use - not that there's anything wrong with v1.7, just that 2.5 is an update...