Thanks for reaching out. In Configuration>Display settings, you have the option to Force errored instances to display red on global overview.
I hope this helps. Please let me know if there are any questions.
Product Support Engineer
Hello @DonFerguson ,
I've discussed this with the team
and it appears that, with the option enabled, a server will always be
red if it's got an error and the error will be visible on the dashboard.
With the option disabled, the server will disappear from the dashboard
if the error causes Monitor to no longer be able to sample it.
Unfortunately, we don't have a full list of all the errors or
circumstances that would cause the server to drop off from the
Tips and how-to guides for Redgate products
Ask, discuss, and solve questions about Redgate's tools
Meet us at an event, get sponsored, and join our Friends of Redgate
In-depth articles and opinion from Redgate's technical journal