After migration to Plesk from another control panel via custom migration framework method, MSSQL databases cannot be managed via myLittleAdmin: the URL cannot be opened in the browser:
Bug in Plesk registered with ID #PPPM-7232.
Subscriptions were created in Plesk with the fake main domains, which are not resolved in DNS (e.g. xxx.package)
The first domain (web space) is always used for MylittleAdmin. Since the domain name is not resolved in DNS, MyLittleAdmin is not accessible.
Until the bug is fixed, the following workaround is available:
Add 'mssql.xxx.package' record in the hosts file on the workstation where Plesk Panel is opened: