First guess is a missing reference.
Select the Modules pane of your Access window.
Open any code module. Open a new one if you must. You want a code window to become open.
Now on the MENU bar, find path Tools >> References
When you open up the References dialog box, you will see a list of modules. Some will be checked. Some will not. Some might have the word "MISSING" as a prefix.
You want to find the ones that are MISSING in that list. When you click (once) to select a module, its file specification including expected path are shown beneath the list area.
You have to try to find the missing modules on your disk somewhere. Use the BROWSE option that is part of the dialog box to find the file.
If the new database is not the same version as the old database, part of your problem might be that the library names changed between versions. In that case, you might have to guess as the newest version.
Example: When I copied some things from an Access 97 database to an Access 2K database, the DAO library changed from file DAO35.TLB to DAO36.TLB, which isn't the same. I had to use the BROWSE option to reconnect my DAO library to the new version of the file. Something similar might apply to your case. The database object exists in DAO for sure. Should also exist in Access library. Not sure where else it would appear.