Challenge 2: A Stale Registered Data Source — Solution Walkthrough

What happens:

Running the merge again using the same registered name fails to
resolve any data — LibreOffice still remembers the registration by
name, but the actual file path it points to no longer exists at that
location, since the file was moved and renamed. The merge either
shows an error indicating the data source can't be found/opened, or
the wizard's address list step comes up empty, since there's no
longer a valid file at the path the registration recorded.

The step needed to fix it:

Re-register the data source: Tools > Options > LibreOffice Base >
Databases, either edit the existing "SampleRecipients" registration
to point at the file's new location and name, or remove the stale
registration and create a fresh one pointing at the correct current
file. Once re-registered (under the same or a new name), the wizard's
Select Address List step can connect to it successfully again.

WHY THIS WORKS AS AN ANSWER
------------------------------
This is a direct, concrete demonstration of this chapter's own warning
box: registration records a FILE PATH at the moment it's created, and
has no mechanism for automatically following a file that's later
moved or renamed — unlike Word's own approach of browsing to a file
fresh each time, which never has anything to go stale in the first
place, since it never remembers a location between separate merge
sessions.