First, let's eliminate mods, as until they are updated by their authors they can cause problems after any new game patch. Please add --disableModding to the game's Steam launch options. Then start a new test city - do you still get these crashes then?
If so, please try this: Rename the "Cities Skylines II" folder in your C:\Users\[user name]\AppData\LocalLow\Colossal Order (to whatever you want) and then start the game. To see the AppData folder you'll need to enable View Hidden Items in File Explorer.
The game will create a new clean CS2 folder and if that works it means that something in your original folder is corrupt and preventing the game from starting. Do NOT delete your original folder though as your saves are stored there and if you want to keep playing you'll need to move them over to the new fresh folder!
Let us know if that helps you. Good luck!
