After getting your latest version, this error message appeared.

Error while loading entity prototype "planted sapling" (tree): No such node (name)
Modifications: Aussybrush > Arborium > eco-trees.

The previous version of your mod had no such error message. (I also left a bug report with the Aussybrush mod dev.)

OK, tell me if this fixes it.
Unzip the Arborium MOD into your "Factorio/Mods" directory

edit the file
Factorio/Mods/Arborium_0.0.4/prototypes/treegen.lua

on line 32 change
if string.find(name, "dead-") == nil then
to
if string.find(name, "dead-") == nil and string.find(name, "planted-sapling") == nil then

(if your text editor doesn't have line references, I would recommend downloading Notepad++)
https://notepad-plus-plus.org/

save file
play Factorio.

I believe that this may fix your issue as line 28 of treegen.lua initiates a change to all entities of type "tree" as the planted sapling is also an entity of type "tree" this code will also change it too, so the above fix should prevent this from happening.

If this doesn't work give us another message and we will try something else :)