Heyho!
I play LSPDFR since two days, and I sat nearly 3 hours at my PC yesterday, trying to figure out, why my game keeps getting stuck in the loading screen after RPH loaded: LSPD First Response: [TRACE] Thread CopManager #1 initialized. I reinstalled GTA and LSPDFR. Nothing. And after I deleted my save files from my Documents folder, I got everything to work again, just without any progress that I've built up. So, it seems like my game always saves a corrupt save file.
This always happens when I save through the Phone, and I always give it like 5 minutes time to save, also if the game already finished saving.
Did something like that happen to you once?