Excuse me for bumping this old topic, but I've had the same issues with any RageNativeUI mods as you and OP describe, and turns out all I've had to do was set GTA5.exe to be ran as administrator, and as I have an EGS version of the game I've also had to run RGL as admin for the game to launch and launch it from RGL first. As a double-safe I've also ran RPH as admin afterwards and with all 3 ran as admin, the crashing stopped and the RageNativeUI based mod menus started working as intended. Posting this for anyone who came here to search for a proper solution, as I've did!