ldbedit can not create new or edit empty databases.
ldbedit -H test.ldb
no matching records - cannot edit
Creating a new database via ldbadd -H testldb ...
and then ldbedit this new database.
This is somehow related to https://bugzilla.samba.org/show_bug.cgi?id=8028.
(In reply to Matthias Dieter Wallnöfer from comment #1)
I tend to agree, this is not a bug but a feature. Perhaps we need a better message, but for now I'm closing this.