Update your video drivers. Complete system freezes are inevitably driver related (or a severe engine bug). The fur isn’t a “plugin” as such and is just a material so issues like that will track back to either a bug or a driver issue.
I use meshes with UVs outside of the 0-1 range all the time.
The fur does work with 4.18 though. I can try sending you my 4.18 version in a private message. How are you adding it to your project? Are you adding it directly from the launcher or moving it between projects somehow?