over 4 years ago - Avanya - Direct link
It's been a long time since I've seen that error. Most likely it's an outdated or incompatible mod that's causing it. The best place to start is to check your mods against this list of known broken and incompatible mods.

https://docs.google.com/spreadsheets/d/1mVFkj_7ij4FLzKs2QJaONNmb9Z-SRqUeG6xFGqEX1ew/edit?usp=sharing


If you don't have any or removing broken mods doesn't help, we'll likely need your output log (called player.log on Mac and Linux) to look closer at your mods.

To easily find the local files for the game, right click your game in the Steam library, select Properties, go to the Local Files tab and select Browse local files.

Windows
\SteamApps\common\Cities_Skylines\Cities_Data\output_log.txt

Mac OS X
Users//Library/Logs/Unity/Player.log

Linux
~/.config/unity3d/Colossal Order/Cities: Skylines/Player.log


Here's a few sites you can upload the file to, which do not require you to sign up first:

https://uploadfiles.io/ - free, no sign-up, can handle large log files
https://paste.ee/ - fast, no sign-up required (some log files will be too large for it though)
https://zerobin.net/ - bit clunky, but can handle huge files, no sign-up required