Which renderer & Evermotion Catalog are you using?
The Library Browser (with the latest Evermotion Catalog add-on installed) is looking for the original folder structure after unpacking. Please unpack all assets (textures & models) with their original folder names into one "parent folder" (maybe that could lead to these "troubles" as their models are delivered "by folder" and these should be maintained). Then you should map the "parent" folder - containing maps folder and your renderer's folder with models (Vray, Mental_Ray, Scanline). Also please note, you shouldn't rename these folders (as our add-on uses that original folder names to allocate corresponding .max files for selected renderer).
In the current version, you need to have available also the V Ray's version of models (if the Library Browser can't find those, you'll get the error "The selected directory does not Contain Evermotion Plants AM* library").
Let me add, that as mentioned here
: "... the Archmodels vol. 154 isn't supported by the Evermotion Catalog, but it shouldn't be hard for you to create your own library ..."
Hope that helps.