The database version will have to match the BioStar 2 version for a database restore to go through properly.
For instance you cannot restore a BioStar 2.4.0 database in BioStar 2.4.1
You will have to restore the 2.4.0 database in BioStar 2.4.0
If you are not sure in which version your database backup was made, you can find some hints in the t_syscfg table of the biostar2_ac database.
In BioStar 2.6 and above, the SYSCFGUID 71,000 will show the BioStar version as below:
However in BioStar 2 versions below BioStar 2.6, you will have to distinguish based on the following values
BioStar 2.3 : 1,000 (SYSCFGUID) - Schema Version (NM) - 85 (VAL)
BioStar 2.4 : 1,000 (SYSCFGUID) - Schema Version (NM) - 99 (VAL)
BioStar 2.4.1: 1,000 (SYSCFGUID) - Schema Version (NM) - 102 (VAL)
BioStar 2.5.0 : 1,000 (SYSCFGUID) - Schema Version (NM) - 102 (VAL)