Example of load order:

*Z_Architect.esm

<..other mods first>

*Z_Horizon.esp (must be loaded first - also requires Z_Architect.esm)
*Z_Horizon_DLC_All.esp (all-in-one DLC module - only use this if you actually own every DLC)

*Z_Horizon_DLC_Automatron.esp (these individual DLC modules can be used if you only own some DLCs)
*Z_Horizon_DLC_Nuka.esp
*Z_Horizon_DLC_Workshop01.esp
*Z_Horizon_DLC_Workshop02.esp
*Z_Horizon_DLC_Workshop03.esp
*Z_Horizon_DLC_FarHarbor.esp

(Don't use the DLC_All and the individual ones at the same time.)

*Z_Horizon_Patch_Architect.esp (required for Architect, but will eventually be obsolete in the future)
*Z_Horizon_Diff_#######.esp (optional difficulty addon - don't use any if you want the default difficulty)
*Z_Horizon_Patch_#######.esp (optional mod compatibility patches)
*Z_Horizon_DEFUI.esp (optional mod - adds icons to crafting menus and component tags to ground items)
*Z_BlurRemoval.esp (optioanl mod to remove screen blurring)
*Z_Extras.esp (optional mod)
*Z_Architect_Extras.esp (optional mod)

Absolutely NEVER do something like this:

*Z_Horizon.esp
*Armorsmith.esp <-- WRONG ORDER - NEVER DO THIS!
*Z_Horizon_Patch_Armorsmith.esp

ALWAYS load other mods BEFORE Horizon, and patches AFTER. There are reasons why this must be done. The patches patch Horizon to support those mods.. NOT the other way around.