Thanks! I didn't have the Rage Plugin Hook installed, so after I installed it and followed its instructions, it gave me the option to load GTA V with the LSPDFR plugin enabled, and it appears to be working properly!
How do I start playing LSPDFR? I have gone through the full installation, accepted the EULA, and had it "reconfigure" itself for me. There is no shortcut to start LSPDFR like there used to be in previous versions, and when I go to a police station, I can't actually go inside and there is no option to go on duty. What am I doing wrong?