As for the problem itself, I'm at the same step as ClonedMew; I've fixed the issue with "Repair Spider Release Lever" by having xEdit Quick Auto Clean clean cctwbsse001-puzzledungeon.esm, though now DynDOLOD's error message complains about some kind of "Altar of the Seasons" (though it returns to the lever thing if I activate the older DynDOLOD output file).
The concerning thing is that this does seem to be an issue with Forgotten Seasons's own plugin. I know a basic amount of how to use xEdit, and going to the FormID that DynDOLOD reports as problematic does reveal that one of its scripts references another FormID that doesn't seem to refer to anything (see attached image).
It would be trivial for me to make a simple patch that changes this value and the similar gap in Repair Spider Release Lever and then distribute it to you guys. But the issue is, I have no idea what was originally supposed to go here.