Hi,
On a fresh installation of version 7.10.4 or 7.10.5, I have a message in the UI Designer instead of the BDM icon on the left, I have an icon with a message on the right that says in french something like : unable to connect to business model, try to restart Studio to solve the error.
Restarting the studio does not change anything, neither reinstalling.
When I check in dev mode in the browser I can see a request to the business data repository in error :