With the release of each major patch to this game most mods become outdated and this means your existing saved games may not work. The solution is to disable your mods and wait for the creators of the mods to update them. In the meantime you can run newer cities with no mods, or only mods that have been updated since the most recent patch.
To remove your mods:
- Open the Content Manager and unsubscribe to all your mods
- Close the game
- Open your installation directory and remove the Addons folder (right click game in Steam > Properties > Browse Local Files). IMPORTANT! Backup the Addons folder to your desktop if you don't want to have to re-download them all again once updated!
- Go to %LOCALAPPDATA%\Colossal Order\Cities_Skylines (PC), /Users/<username>/Library/Application Support/Colossal Order/Cities_Skylines (Mac), /home/<username>/.local/share/Colossal Order/Cities_Skylines (Linux)
- Delete the Addons folders from the above locations
- Restart the game
If this doesn't solve it a complete re-installation may be needed (and is highly recommended):
- Remove the game from Steam (delete local content)
- Manually delete all these files and folders, if still there:
(first move the /saves/ folder elsewhere to keep your save games)
It should work fine now (but with no mods) and you can then add mods one by one to see which one is broken or wait for the creators to update them all.
Mods are created by the community and as such we are not able to ensure that they are always up to date and compatible, they are used at your own risk.