Bind918 slave reports Dumping master file...open: file not found

A releng/14 armv7 system using bind918 from pkg has been
configured as a slave. The  zone files were moved from a
bind913 installation to the default /usr/local/etc/namedb. 
Transfers from the master seem to work and the slave answers 
queries.
 
The options section of named.conf contains:
        directory       "/usr/local/etc/namedb/working";
        pid-file        "/var/run/named/pid";
        dump-file       "/var/dump/named_dump.db";
        statistics-file "/var/stats/named.stats";
        recursion no;


The files and directories  exist with reasonable permissions:

# ls -ld /usr/local/etc/namedb/working
drwxr-xr-x  2 bind bind 512 Feb 16 15:29 /usr/local/etc/namedb/working

# ls -l /var/run/named/pid
-rw-r--r--  1 bind bind 5 Feb 16 15:29 /var/run/named/pid

# ls -l /var/dump/named_dump.db
-rw-r--r--  1 bind bind 0 Feb 16 15:28 /var/dump/named_dump.db

After stopping and restarting named /var/log/messages still contains:
....
Feb 16 15:35:38 ns2temp named[3730]: all zones loaded
Feb 16 15:35:38 ns2temp named[3730]: running
Feb 16 15:35:38 ns2temp named[3730]: dumping master file: slave/tmp-GJCoWCIfkq: open: file not found
Feb 16 15:35:38 ns2temp named[3730]: managed-keys.bind.jnl: open: permission denied
Feb 16 15:35:38 ns2temp named[3730]: managed-keys-zone: keyfetch_done:dns_journal_open -> unexpected error
Feb 16 15:35:38 ns2temp named[3730]: managed-keys-zone: error during managed-keys processing (unexpected error): DNSSEC validation may be at risk
Feb 16 15:35:38 ns2temp named[3730]: checkhints: b.root-servers.net/A (170.247.170.2) missing from hints
Feb 16 15:35:38 ns2temp named[3730]: checkhints: b.root-servers.net/A (199.9.14.201) extra record in hints
Feb 16 15:35:38 ns2temp named[3730]: checkhints: b.root-servers.net/AAAA (2801:1b8:10::b) missing from hints
Feb 16 15:35:38 ns2temp named[3730]: checkhints: b.root-servers.net/AAAA (2001:500:200::b) extra record in hints
Feb 16 15:35:38 ns2temp named[3730]: dumping master file: slave/tmp-Q6Y3sYziKE: open: file not found
Feb 16 15:35:38 ns2temp named[3730]: dumping master file: slave/tmp-vASSKxorvs: open: file not found

The "...file not found..." errors repeat at intervals. The checkhints errors appear
harmless since the server is not recursive. 

I did not adopt the convention of naming directories primary and secondary, sticking
with the old master and slave nomenclature. Could that be the culprit? I'm hesitant
to mess with zone files that work 8-)

Any hints on where to look in the man pages would be much appreciated. I thought
there was a configuration test somewhere in the bind package but don't find it.

Thanks for reading,

bob prohaska