SQLite/SQL Compact Toolbox cannot connect inside program

Question

SQL compact database 4.0 installed, as well as the tool, and it seems to be functioning in toolbox.
Can create tables and stuff, but when I try to use it from C#, it cannot connect.

I get an error - after pointing to the file and checking the connection, which is OK:

 

An error occurred while retrieving the information from the database.
The specified type is not supported by this selector.

All new to Visual Studio but not to databases or SQL.