Let me add, that this connection string was working with Office 2013:
OLEDB CONNECT32 TO [Provider=Microsoft.ACE.OLEDB.15.0;Data Source=C:\Users\matthias\Documents\db.accdb;]
Simply changing the version number to 16.0 doesn't work either:
OLEDB CONNECT32 TO [Provider=Microsoft.ACE.OLEDB.16.0;Data Source=C:\Users\matthias\Documents\db.accdb;]
Result is: connection failed
i haven't tried an OLEDB connection to access office 16.0 but i think you can create an ODBC connection to it as a system DSN and select 'ODBC' from qlik sense.
One thing though regarding your existing OLEDB connection.. i noticed you are using CONNECT32 in the syntax above which is a 32 bit connection. you may need just a CONNECT (for 64 bit) .
Back to ODBC, you may need to form the ODBC DSN using the 64 bit ODBC administratorin order for qlik sense to see it. Many modern windows machines have both a 32 bit and a 64 bit ODBC administrator program and i suggest choosing the latter.
I installed the 32 bit Office version and therefore I'm using the 32 bit driver-
found that the ODBC driver for Access was gone when using ODBC administrator as you suggested.
So I installed "Microsoft Access Database Engine 2010 Redistributable" and defined a User DSN.
With the defined User DSN and ODBC now I can access the database.
Thanks for your hints.