@Kristin Scheucher, this is a bit confusing.
It appears you have Confluence Cloud, but you're entering a URL into the Navigator as-if you had it on-premise (jira.domain.com instead subdomain.atlassian.net). Furthermore, you do not configure Application Links in the Application Navigator. You must navigate to Administration and configure the Application Link there instead.
When using Cloud, I think your best bet is to contact support. That error message is pretty useless without a log. And you can't access a log in Confluence Cloud, from what I know. See here: https://answers.atlassian.com/questions/112862
Hi my Community friends! For those who don't know me, I'm a product marketer on the Confluence Cloud team - nice to meet you! For those of you who do, you know that I've been all up in your Co...
Connect with like-minded Atlassian users at free events near you!Find a group
Connect with like-minded Atlassian users at free events near you!
Unfortunately there are no AUG chapters near you at the moment.Start an AUG
You're one step closer to meeting fellow Atlassian users at your local meet up. Learn more about AUGs