Using serial connection on the simulator

I am getting this error:

I have tried chmod 777 /dev/ttyS1, with ttyS1 being the virtual serial port that my device is communicating with

If I run ./start-ursim.sh with sudo, it gets passed this command without the permission denied error. I read though, that the sim should not be run in sudo, and it does not seem to run correctly anyways.

Is there any way to get passed this permission denied for serial ports when using the sim?
I am using a RS485 device and the related code is in the python daemon using pyserial