How can I fix this error I get it everytime

Hi I am sorry if this has been asked many times before however I am getting really annoyed with this error. I get it whenever I go to run a project or even edit the run configuration. I have added it as a picture as it is probably a lot easier to read that way compared to copying it in, if you could tell me how to stop it or point me in the right direction that would be great, pretty new to all of this.