you can only open a database with same version or lower.
if you have a2007 you can only open a2007 and lower version.
if a2019, a2019 and lower.

a db created using a2019 cannot be opened in a2007, since there are Newer system tables
in a2019 that cannot be found in a2007.

if the original db was created in a2007, then modified the code/tables in a2019, it
might not be compatible with a2007 anymore.