JavaScript error occurred in the main process

[martemaniac]

I've been playing Cities Skylines for many years and this is the first time I get this error. JavaScript error occurred in the main process. it says error: Cannot open C: (etc) Does anyone know what the heck is this? how could I fix it?

[spencerssa]

https://steamcommunity.com/app/255710/discussions/0/3115896179312327904/