Because "new" is relative and the modding scene changes often, here is the current breakdown of the situation regarding Four-Play and F4SE plugins.
Fix: This is almost always caused by an outdated version of LL Fourplay or failing to use the community-updated version of AAF required for your specific game build. Check the specialized AAF setup guides and Discord servers on LoversLab to get the specific package files mapped to your current patch. ll fourplay f4se plugin new
Fallout 4 Script Extender (F4SE): The foundation for the plugin. Because "new" is relative and the modding scene
How to Install F4SE for Fallout 4 (2018) - Script Extender v0.6.6 24 Mar 2018 — Fallout 4 Script Extender (F4SE) : The foundation
If you are running the Next-Gen version of Fallout 4, look specifically for the updated "Community F4SE Plugin" files or beta versions explicitly labeled for Next-Gen compatibility.