Restore fails with error "The media set has 2 media families but only 1 are provided. All members must be provided."

When you try to restore a backup, it might fail with the below error.

Msg 3132, Level 16, State 1, Line 1  The media set has 2 media families but only 1 are provided. All members must be provided.  Msg 3013, Level 16, State 1, Line 1  RESTORE DATABASE is terminating abnormally.

This means that the backup file provided for restore is not a complete one.

Okay, now what does "is not a complete one" mean?

This error pops up when the database is backed up into different files using the split backup technique.
In this case, the database backup was split into 2 files and while restoring the database only one file was mentions.
To fix this issue, you have to specify the complete list of backup files which were part of the backup procedure.