Backup is corrupted

Symptoms

1.  Backup to an archive of version 12 format fails with the following message:

The file is corrupted

2. You expand activity details and in the line "Failed to open archive" you see a file with .tibx extension, for example:
error 0x400355: Failed to open archive 'Acronisbackup.tibx'.

Instructions on how to troubleshoot and resolve issues with corrupt backups

Symptoms

Backup or a different operation (replication, recovery, etc) fails with the following error:

The archive is invalid or its type is unsupported