I got this error when adding this mod to my game

Failed to load mods: Error while loading item prototype "automation-science-pack" (tool): Spoiling is disabled and can not be used.
Modifications: Base mod › Science spoils into lower tier science

I'm using some of Bob's mods, I'm still new to this game

on second thought, maybe the spoiling mechanic is added by space age dlc, which I don't have

Yes I forgot about that. Fixed now.

you probably want to have spaceage(or the extended feature flags mod) as a dependency since spoilage is a spaceage thing

The only declared use of the feature-flag mod seems to be avoiding the need to publish separate mods on the mod portal depending on whether the DLC is owned or not.
Your report suggested that the engine gave you an error saying that spoilage required the DLC, so I added the line "spoiling_required": true to the info.json.
So yes, I have already done that—but it looks like you haven’t updated the mod.
I do not add a dependency on the Space Age mod or any other overhaul mod in general, since the code should work regardless.