And what I did last time, was press compile (Next to play), in the bottom right it said compile complete, then I clicked save, after save complete I closed UE4
Just disable the plugin by editing the uproject file in a text editor. Do you have the source code for “Fur”? If so then you will probably need to compile the plugin separately from visual studio. If not then you’ll have to wait for a 4.21 compatible version.