Users with the mid_server role are unable to see the MID Server module in the left navigation.
The MID Server module is visible for users with roles admin and agent_admin. To see the MID server modules, the mid_server role is not required.
Add the admin or agent_admin role to the users who need to see the MID server module.
If you see this error for users with mid_server role:
"User <user_id> with mid_server role successfully connected but is not associated with a MID Server"
Please review KB0725181 - MID server error "User #### with mid_server role not associated with a MID Server" after London upgrade article for the solution.