If you’re doing both “Lightning and Weather” and “Post-Processing”, the required update file for “Cathedral Weathers and Seasons” has been moved to its own, separate page on Nexus: https://www.nexusmods.com/skyrimspecialedition/mods/116019
You need to install this as it’s a required dependency for one of the STEP patches.
If someone who has permissions to edit the guide could update it accordingly, that would be awesome-sauce ☺️