Community Tip - Your Friends List is a way to easily have access to the community members that you interact with the most! X
Just looking at the screenshot, we may not be able to predict the root cause. I would request to attach your ThingWorx Studio logs.
The credentials of your Studio portal (https://studio.thingworx.com) should be used over here. Also, to further validate the credentials, append "/ExperienceService" to the URL in the ExperienceService field and try accessing it from your browser.