inform users they're logged in somewhere else when failing concurrent logins
When a user might attempt to log into their account from a second computer (or VM), its appropriate to fail their login on the second computer. Right now, there is no indication that this has occurred because they're already logged in elsewhere. The error talks about adding Gearset IPs to Salesforce, but the issue is being logged in already.
I suggest telling us we're already logged in. It's easy to forget!