ArduSub Link 1 Down

Hello, I am trying to run gazebo and ardusub together. Gazebo works fine but when I run the SITL I get link 1 down. I can not run the SITL separate either or with qdgroundcontrol, I get the same error message. I have looked at some past posts here and tried to follow the fixes but none seem to work for me. Any ideas would be appreciated.