Updated with a list of broken mods. Please check the spreadsheet for the latest information
https://pdxint.at/BrokenModCS

Originally posted by jetjockey89: I have had to completely uninstall this game and unsubscribe from all content because my game won't even load now (with or without modding). I moved a copy of my save game to my desktop so I wouldn't lose the 180+ hours of work I've put into it. Now that I have redownloaded the game, I can't get the save file back to the appropriate file location. It's almost as if it doesn't exist anymore. I am beyond frustrated with this. Who do I talk to about a full refund? What a colossal waste of time this has been....

Refunds are handled by the store you bought the game from. With 180+ hours in the game I'm afraid you're probably not eligible for a refund most (if not all) places. Instead, I recommend you make a report on our support forum, explain the situation and what you have tried, and attach the save there.
https://forum.paradoxplaza.com/forum/forums/support-bug-reports.879/

Originally posted by ghydan: These mods don't work, because harmony is not updated.
-Adaptive Networks (AN) V3.17.5-5 (STABLE) instead
-Loading Order Mod V1.15.7 (STABLE) instead
-Extended Managers Library temporary fix instead
-Prop Anarchy temporary fix instead
-Tree Anarchy temporary fix instead

As far as I'm aware Harmony is not broken. If you have issues with it I recommend unsubscribing the mod, let Steam remove its files, and subscribe to it again. Also make sure to check your mods against the list of known broken mods and make sure you don't have old versions installed. Lastly, the mods mentioned require Extended Managers Library. The original version is broken, please use this one instead:
https://steamcommunity.com/workshop/filedetails/?id=2949127226

Originally posted by Meesmoth: Some of the mod authors also start refusing to update their mods only due to the CS2 announcement, such as Keallu, known for his "It!" mods like Measure It!, etc.

Most of Keallu's mods were updated yesterday.

For everyone:
I'm super strict about replies here. If you want to provide feedback on our support of the game, you are welcome to start a thread on that, but I will remove those kinds of comments here to keep this thread focused on helping people who have issues with their mods. Please stay on topic in here, thank you! :)

Originally posted by riaantimson: The game is unplayable for me since the update. Mods list disappears and resets in an endless loop. I bought all 3 DLC within the first hour of launch and I am yet to enjoy any of it. Unique building relocks themselves too, so this is thrown into the loop of trying to load my current city properly, which I have not managed once since the update.

We're aware of the issue with mods resetting and currently investigating it. When we have an update I will let you know, but for now I recommend enabling mods in small batches, backing up the userGameState file, and restarting the game between each batch. If the userGameState file is suddenly 0KB then it's been corrupted and should be replaced with your latest backup.To back it up copy it from its location to somewhere else. To replace it copy it back into the following folder:
C:\Users\%username%\AppData\Local\Colossal Order\Cities_Skylines

Originally posted by KingKong TV:4125025: How to remove the new DLC. There are some significant issue to break saved game.

Removing the DLC will not change the version of the game and is very unlikely to solve anything. Are you using any mods?

Originally posted by KingKong TV:4125025:

Originally posted by CO_Avanya: Removing the DLC will not change the version of the game and is very unlikely to solve anything. Are you using any mods?

Yes.

If you haven't already, then you will need to check your mods against the list of known broken mods. Some mods are still needing an update and some have been replaced by newer ones. I recommend you check both the first tab and the tab named Patch 1.16.1. Unsubscribe broken ones, get replacements where available, and make sure to enable the new mods.
https://pdxint.at/BrokenModCSAnd if you've already done that or it doesn't help, please let me know. :)

Originally posted by Simuscape: Haven't tested my game today, but when I tried yesterday I ran in to the now infamous "loop" as many others. But I also noticed that all my assets were left ontouched, (i.e not gone or disabled), but with one exception; ALL assets were enabled - even those I've had disabled from before the patch update).

The advice given about resub mods one or two at a time and at the same time backing up the userGameStat-file will, as far as I understand, hopefully add all mods back to the game. But in the end, doesn't the userGameStat-file contain my specific settings for my game saves, so even though I manage to resub to all mods again, my settings are gone? And I will have to go through the long list of assets and disable those that were disabled in the first place?

With all this in mind, aren't I better off waiting for CO to find out about the problem altogether?

If your userGameState has reset, then it no longer contains the information about which mods are enabled and which ones are disabled. Mods are off by default while assets are on by default, so that's what you will see after a reset.Unsubscribing/resubscribing mods you had before won't affect the userGameState file, they are already listed there. New mods will be added to the list though. But if your file has already reset, then it doesn't really matter. The 0KB file is empty, so the list starts over.For now, I recommend enabling your mods in small batches, backing up the userGameState file, and restarting the game between each batch. If the userGameState file is suddenly 0KB then it's been corrupted and should be replaced with your latest backup.To back it up copy it from its location to somewhere else. To replace it copy it back into the following folder:
C:\Users\%username%\AppData\Local\Colossal Order\Cities_SkylinesOr you can of course wait, but I'm afraid I don't have any info about how long a wait that might be.