Open your game folder, then the MODS folder, then 100_FalloftheRisingSun_Ultimate... folder (doesn't matter which version you are using), then the Support folder in that, and find the "ActivatingFOTRSU.pdf" file. Double-click on that, and it should open in your default browser just fine, even if you do not have a pdf viewer app. If the un-zipped mod folder is not in there, it should be. You should NOT be seeing "... I get the red bar on the original U-boat missions splash screen..." at all - only the FotRSU splash screen with the USS Sea Devil (SS-400) surfacing in the middle, and when that finishes, you should be at the menu page. You should NOT have any issue getting to the menu page. Generally speaking, if you crash before that, then the mod is not activating correctly for whatever reason. If you crash after that when loading the 3D portion of the game, then you most likely have a DirectX issue.
One of the only other things I can think of that ~might~ be causing you an issue is the display for your computer itself - but you still should NOT be seeing the Stock splash screen, only FotRSU. While in the game folder, right-click on the SH4.exe file, and then left-click on the "Properties" choice at the bottom of that context menu. Click on the "Compatibility" tab at the top of that "Properties" window, and compare to what this is:
You will have to experiment with the settings because it is all computer dependent, but usually, you can almost guarantee yourself that you will have to click the "Change high DPI settings" on the middle window there (which is the "Properties" first page). The top window is what you get after clicking that button, and again, what you click will depend upon your computer. What you see I have clicked there is for the computer I am currently on. On one of our laptops, I also have to click the "Program DPI - Use this setting to fix scaling problems..." and then use the "User the DPI that's set for my main display when:" and then use the drop-down box and choose "I open this program". All of the settings there are dependent upon the OS Build, the video card, and the display, as to what you need to use.
The last thing is a question: What version of FotRSU are you trying to activate, or do you by chance have a version of FOTRS? This thread is for "Fall of the Rising Sun Ultimate (Edition)", while the other is the original mod "Fall of the Rising Sun" from the AOTD_MadMax team, which FotRSU is based upon - but they are two different mods. MadMax built a version of his mod (FOTRS v2.x) for SH4 v1.4, and that can and does cause issues if you attempt to use it on v1.5 of the game...
Let us know! - oh! and you do need a 64-bit version of Windows and 4Gig of RAM - at a minimum. If you don't, let us know your computer details... In the meantime, I going back into absolute frustration trying to test the ST periscope radar... sigh
