Treesloth Missing in Rhino 6 r19

Dear all,

I just realize I cannot find any Treesloth components anymore in grasshopper w/ rhino 6 r19…
I have double check and quite sure I have copy the treesloth plug-in into my libraries folder.
I remember I can still use those components previously when I am using rhino 6 r13.
Did any one has the same issue and know how to fix it?

Thanks you in advance.

Jack