In Rimworld specifically I have somewhere on the order of 1.2k subscriptions, and Steam does not like that very much. There are several mods that I know, for a fact, I am subscribed to (even mods that I know for a fact I had downloaded just 10 minutes ago, because they were IN my active mods list but now when I click 'sort' in Rimsort it says I'm missing dependencies) that nevertheless are not actually downloaded anymore because after Steam 'verified' the game (which as far as I can tell also tries to 'verify' the workshop content for the game) they must've gotten deleted or something.

So far the only way I've found to get Steam to actually download these mods is to manually unsubscribe and resubscribe to them, in which case Steam just downloads them like it should have already.

Is there any reliable way to force Steam to actually download all of your workshop subscriptions? There are a lot of minor mods that I could totally forget about when building up a pack and I often don't even realize are missing at first until I realize that there is definitely a feature that I remember having and I have not seen anywhere in this mod list.

edit : example set of errors I got in Rimsort after launching the game and closing it, which prompted Steam to do an automatic verify
"""
Could not find data for some mods!

The following list of mods were set active in your mods list but no data could be found for these mods in local/workshopmods paths. Are your game configuration paths correct?

* deadmano.rimanoarchitecticons
* vanillaracesexpanded.waster
* void.morethancapable
* owlchemist.smartfarming
* hellrevenger.batchinstall
* thelastbulletbender.saddleup2
* ilyvion.realisticorbitaltrade
* sambucher.selectivebioregeneration
* lmgginspace.responsiblesleepers
* leoltron.explicittimings
* darkshadow44.surgeryimproved
* amegakull.hardymetals
* sicefe.senseofdepth
* kathanon.moregeneinfo

"""
and, again, I unsubscribed from zero mods, subscribed to zero mods, changed nothing in rimsort, modified no files, etc. All I did was run the game and wait for Steam's verification to complete after I closed it. I had all of these mods, then Steam did it's magic, and then I didn't.