Required key not available

[David Matthews]

hello 

dovecot -n
# 2.3.4.1 (f79e8e7e4): /etc/dovecot/dovecot.conf
# Pigeonhole version 0.5.4 ()
# OS: Linux 4.19.0-12-amd64 x86_64 Debian 10.0 


what is the meaning / cause of this in mail.err:-
----------------------------------------------------------
dovecot: imap(david)<5004><vCVKAtO2UI1/AAAB>: Error: Mailbox Trash: open() failed with mbox: Required key not available
----------------------------------------------------------

I can telnet to port 143, log in and list folders, but cannot open them.

This seems to have resulted from an experimental install (now purged) of courier-imap (I maintain a webmail program). Before this, dovecot just worked; now this problem remains even after a reinstall.

--
David Matthews
mail at dmatthews.org