I'd suggest to read this:
ActiveX component can't create object[
^]. There you'll find 5 reasons which may cause such as error message.
Another reason...
Sometimes, when MS Access database is used on workstations (computers) without full version of MS Access, you may need to reinstall (repair)
MS Access 2010 Runtime[
^].
You have to provide more details about your dlls. Without knowing its names versions etc., we can't help you...