Acronis Backup 12.5: SQL backup fails with "Failed to get additional information from file"

Symptoms

1. You try to back up SQL databases: either by selecting databases directly or using disk-level backup with enabled Microsoft SQL Server application backup
2. Backup fails with the following error:

   Backup failed.
   Failed to get additional information about file 'D:\MSSQL\03\Database1.mdf'.

3. SQL QUERY SELECT @@SERVERNAME as SERVERNAME retruns old hostname or null

   To check this, execute the following SQL query while connected to an instance in question: