The backup is incompatible with current server. Please upgrade your database engine or choose a different SQL server.

"The backup is incompatible with current server. Please upgrade your database engine or choose a different SQL server." 

This message prompt when doing restore.

Reason: You’re using different SQL version with the one that you get the backup file from.

Eg: You’re using SQL Server 2008 R2, they using SQL Server 2012 

1. Please check your current SQL Server Version.

      Get in C:\Program Files\Microsoft SQL Server / C:\Program Files(x86) \Microsoft SQL Server

      The first digits refer to the version of SQL Server such as:

• 8.0 for SQL Server 2000
• 9.0 for SQL Server 2005
• 10.0 for SQL Server 2008
• 10.5 for SQL Server 2008 R2
• 11.0 for SQL Server 2012
• 12.0 for SQL Server 2014
• 13.0 for SQL Server 2016

Example as below:

2. Install SQL Server version that needed to restore database

Download link as below:

https://www.microsoft.com/en-my/

Download and install.

Please refer How to Install SQL Server 2012 express